Electromechanical power switch integrated circuits and devices and methods thereof

ABSTRACT

An electromechanical power switch device and methods thereof. At least some of the illustrative embodiments are devices including a semiconductor substrate, at least one integrated circuit device on a front surface of the semiconductor substrate, an insulating layer on the at least one integrated circuit device, and an electromechanical power switch on the insulating layer. By way of example, the electromechanical power switch may include a source and a drain, a body region disposed between the source and the drain, and a gate including a switching metal layer. In some embodiments, the body region includes a first body portion and a second body portion spaced a distance from the first body portion and defining a body discontinuity therebetween. Additionally, in various examples, the switching metal layer may be disposed over the body discontinuity.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation application of U.S. patentapplication Ser. No. 15/240,799, filed Aug. 18, 2016, now U.S. Pat. No.9,793,080, which claims benefit of both U.S. Provisional PatentApplication No. 62/206,712, filed Aug. 18, 2015 and U.S. ProvisionalPatent Application No. 62/328,525, filed Apr. 27, 2016, and is alsorelated to U.S. patent application Ser. No. 13/975,216, filed Aug. 23,2013, now U.S. Pat. No. 8,786,130, the entire disclosures of which areincorporated herein by reference.

BACKGROUND 1. Technical Field

The present invention generally relates to semiconductor devices. Moreparticularly, the present invention relates to the integration ofmicro-electromechanical systems (MEMS) or nano-electromechanical systems(NEMS) with metal-oxide-semiconductor (MOS) devices and processes.

2. Description of the Related Art

The ever increasing demand of small, portable multifunctional electronicdevices has led to the continued proliferation of smart phones, personalcomputing devices, personal audio devices (e.g., MP3 players), as wellas biomedical and security devices. Such devices are expected to supportand perform a greater number of increasingly complex and sophisticatedfunctions while consuming less and less power. Such electronic devicesrely on limited power sources (e.g., batteries and/or alternative energyharvesting systems) while providing ever-increasing processingcapabilities and storage capacity.

In an attempt to reduce overall integrated circuit (IC) powerconsumption, various power gating techniques have been introduced todisable current flow to IC devices and circuitry when not in use, forexample, when the device is in a non-operation mode so as to reducestandby consumed power. One common power gating technique includes usingMOS transistors to switch connections to power or ground networks ON andOFF. The power gating technique can be understood with reference to FIG.1, which shows a MOS power gate 102 coupled to a circuit block 104,where the MOS power gate 102 controls the power supplied to the circuitblock 104 from a voltage supply (V_(DD)) by way of the gate controlsignal at an input of the MOS power gate 102. For example, in somecases, when the gate control signal is low (logic 0), the MOS power gate102 is ON, and a virtual V_(DD) coupled to the circuit block 104 isapproximately equal to V_(DD). Alternatively, in some cases, when thegate control signal is high (logic 1), the MOS power gate 102 is OFF,and the virtual V_(DD) is approximately zero, thus effectively turningoff of the power supplied to the circuit block 104. While the example ofFIG. 1 shows the MOS power gate 102 connected between the circuit block104 and the power network (V_(DD)), the MOS power gate 102 could also becoupled between the circuit block 104 and a ground connection (V_(SS)).Power gating of electronic devices becomes particularly important fordevices that rely on limited power sources, spend a majority of theirtime in an OFF state or sleep mode (i.e., a non-operation mode), andwhich only operate on periodic and/or event-driven schedules, such asfor example, motion-detecting security systems and biological implantswhich may only infrequently collect/analyze data or provide a drugrelease, among others.

The most common way to implement power gates has been through the use ofMOS transistors, as illustrated in FIG. 1. However, as the minimumfeature size of MOS devices has continuously decreased in an effort tomeet stringent demands on device performance and power consumption, theOFF state leakage current has increased, and is rapidly approaching ONstate current levels. This increased OFF state leakage, together withthe fact that many electronic devices are spending a majority of theirtime in a non-operation mode, results in a dominant source of powerconsumption being the OFF state leakage occurring while the device is ina non-operation mode. Moreover, the voltage drop present in MOS deviceswhile in an ON state can significantly degrade device performance,particularly in aggressively scaled and embedded IC devices.

SUMMARY

The problems noted above are solved in large part by use of anelectromechanical power switch (e.g., a MEMS/NEMS device) forcontrolling power to monolithically-integrated circuit (IC) devices, asdetailed in U.S. patent application Ser. No. 13/975,216, entitled“METHOD OF FORMING AN ELECTROMECHANICAL POWER SWITCH FOR CONTROLLINGPOWER TO INTEGRATED CIRCUIT DEVICES AND RELATED DEVICES”, filed Aug. 23,2013, now U.S. Pat. No. 8,786,130, the entire disclosure of which isincorporated herein by reference.

Additional problems presented by existing power gating processes anddevices are solved by embodiments of the present disclosure. Forexample, at least some of the illustrative embodiments of the presentdisclosure include using such monolithically integrated MEMS (I-MEMS)and/or integrated NEMS (I-NEMS) devices as integrated decouplingcapacitors. In some examples, a given I-MEMS/I-NEMS device may be usedas a power gate during a first time and as a decoupling capacitor duringa second time. In some embodiments, conversion of the I-MEMS/I-NEMSdevice between the power gate and decoupling capacitor function may beperformed automatically (e.g., via a control circuit, software, etc.) ormanually (e.g., via user input). In some cases, a plurality ofI-MEMS/I-NEMS devices may be implemented simultaneously, and thefunction of each of the I-MEMS/I-NEMS devices may be individuallycontrolled. Thus, for examples, some embodiments may include one or moreI-MEMS/I-NEMS devices functioning as power gate devices, whilesimultaneously including one or more I-MEMS/I-NEMS devices functioningas decoupling capacitors.

Other illustrative embodiments include using redundant I-MEMS/I-NEMSdevices to serve as redundant power gates. For example, a given ICdevice (e.g., CPU, GPU, etc.) may include a first set of I-MEMS/I-NEMSdevices that serve as a primary power gate and decoupling capacitor(s)and a second set of I-MEMS/I-NEMS devices that serve as a secondarypower gate and decoupling capacitor(s). In some cases, the secondarypower gate may be used when the primary power gate fails. In someembodiments, when the secondary power gate is not in use, the secondarypower gate may be converted to use as a decoupling capacitor.

Yet other illustrative embodiments include using a plurality ofI-MEMS/I-NEMS devices to enable a multi-supply I-MEMS/I-NEMS switch,which includes a power gating schemes that would not be practical withconventional MOS technology. For example, in some embodiments, theplurality of I-MEMS/I-NEMS devices may be used as power gates to controlpower to/from a plurality of power supplies. In various embodiments,such multi-supply I-MEMS/I-NEMS switches may be alternately used asdecoupling capacitors and/or combined with additional I-MEMS/I-NEMSdevices used as decoupling capacitors.

Still other illustrative embodiments include using I-MEMS/I-NEMS devicesto enable an anti-stiction switching method as well as a 3-D decouplingcapacitor. It is understood that the above summary containssimplifications, generalizations and omissions of detail and is notintended to be a comprehensive description of the claimed subject matterbut, rather, is intended to provide a brief overview of some of thefunctionality associated therewith. Other systems, methods,functionality, features and advantages of the claimed subject matterwill be or will become apparent to one with skill in the art uponexamination of the following figures and detailed written description.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the various embodiments, the detailedwritten description can be read in conjunction with the accompanyingfigures. It will be appreciated that for simplicity and clarity ofillustration, elements illustrated in the figures have not necessarilybeen drawn to scale. For example, the dimensions of some of the elementsare exaggerated relative to other elements. Embodiments incorporatingteachings of the present disclosure are shown and described with respectto the figures presented herein, in which:

FIG. 1 shows a schematic diagram of a MOS power gate coupled to acircuit block;

FIG. 2A shows a schematic diagram of an electromechanical power gatecoupled to a circuit block, in accordance with some embodiments;

FIG. 2B shows a schematic diagram of an electromechanical power gate,with integrated decoupling capacitors, coupled to a circuit block, inaccordance with some embodiments;

FIG. 2C shows a schematic diagram of an electromechanical power gate,with integrated decoupling capacitors, coupled to a circuit block and/oran integrated circuit (IC) device, in accordance with some embodiments;

FIG. 3 illustrates a schematic representation of an exemplary CPU/GPUpower management system according to some embodiments;

FIG. 4 provides a block diagram representation of an example dataprocessing system within which one or more of the described embodimentsmay be practiced;

FIG. 5 shows a schematic diagram of a four-terminal (4T)electromechanical switch and cross-section diagrams illustrating theoperation of the 4T switch;

FIGS. 6A, 6B, 6C, and 6D illustrate a MEMS/NEMS device having integrateddecoupling capacitors, according to some embodiments;

FIG. 7 shows a top-view of a device which may include an array ofembedded/integrated electromechanical power switches and a plurality ofintegrated decoupling capacitors, according to some embodiments;

FIGS. 8A/8B and 9A/9B illustrate an example of a device, such as thedevice of FIGS. 6A, 6B, 6C, and 6D, in operation as well as equivalentcircuits corresponding to a particular operational state, according tosome embodiments;

FIGS. 10A/10B and 11A/11B illustrate an example of using devices of thepresent disclosure to implement a dual power-gate/decoupling capacitorcircuit, according to some embodiments;

FIG. 12 illustrates an example of using devices of the presentdisclosure to implement a redundant integrated MEMS/NEMS power gatingcircuit, according to some embodiments;

FIGS. 13A/13B and 14A/14B illustrate examples of using devices of thepresent disclosure to implement a multiple power supply switch circuit,according to some embodiments;

FIGS. 15A/15B and 16A/16B illustrate examples of using devices of thepresent disclosure to implement an anti-stiction switching circuit,according to some embodiments,

FIGS. 15C/16C illustrate an equivalent circuit of a conventionalMEMS/NEMS device, and

FIGS. 15D/16D illustrate an equivalent circuit of a MEMS/NEMS devicecorresponding to embodiments of the present disclosure;

FIGS. 17A, 17B, 17C, and 17D illustrate a MEMS/NEMS device havingintegrated decoupling capacitors, including a plurality ofopenings/holes, according to some embodiments;

FIG. 18 shows a top-view of a device which may include an array ofembedded/integrated electromechanical power switches and a plurality ofintegrated decoupling capacitors, including a plurality ofopenings/holes, according to some embodiments;

FIG. 19 is a flow chart of a method of fabricating a MEMS/NEMS devicehaving integrated decoupling capacitors, or portion thereof, accordingto one or more aspects of the present disclosure;

FIGS. 20A, 20B, 20C, 21A, 21B, 21C, 22A, 22B, 22C, 23A, 23B, 23C, 24A,24B, and 24C include top-down and cross-section views of an embodimentof a MEMS/NEMS device having integrated decoupling capacitors accordingto aspects of the method of FIG. 19;

FIGS. 25A, 25B, 25C, 25D, and 25E illustrate a method of fabrication ofa 4-terminal MEMS/NEMS device, according to some embodiments;

FIG. 26 illustrates an exemplary embodiment of an integratedMEMS/NEMS-decoupling capacitor cell, according to some embodiments;

FIG. 27 illustrates a MEMS/NEMS device having integrated decouplingcapacitors with a plurality of 3-D features, according to someembodiments;

FIG. 28 is a flow chart of a method of fabricating a MEMS/NEMS devicehaving integrated decoupling capacitors with a plurality of 3-Dfeatures, or portion thereof, according to one or more aspects of thepresent disclosure;

FIGS. 29A, 29B, 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 30J, and 30Kinclude top-down and cross-section views of an embodiment of a MEMS/NEMSdevice having integrated decoupling capacitors, with a plurality of 3-Dfeatures, according to aspects of the method of FIG. 28;

FIGS. 31 and 32 illustrate capacitance values versus capacitor area, forcapacitors having a variety of oxide thickness and a variety ofdielectric materials, in accordance with some embodiments;

FIG. 33 provides a table showing properties of SiO2 and Si3N4, which aretwo of a plurality of materials that may be used in the implementationof one or more of the embodiments of the present disclosure;

FIGS. 34A/34B illustrate a MEMS/NEMS device having integrated decouplingcapacitors, including an input decoupling capacitor having a larger areathan an output decoupling capacitor, according to some embodiments;

FIG. 35 shows a top-view of a device which may include an array ofembedded/integrated electromechanical power switches and a plurality ofintegrated decoupling capacitors, including an input decouplingcapacitor having a larger area than an output decoupling capacitor,according to some embodiments;

FIGS. 36A/36B illustrate a MEMS/NEMS device having integrated decouplingcapacitors, including an input decoupling capacitor while not includingan output decoupling capacitor, according to some embodiments;

FIGS. 37/38 illustrate a top-view and cross-section view, respectively,of a 3D (e.g., vertical) multi-layer capacitor, according to someembodiments;

FIGS. 39/40 illustrate a top-view and cross-section view, respectively,of an array of 3D (e.g., vertical) multi-layer capacitors, according tosome embodiments;

FIGS. 41, 42, 43, 44, 45, 46, 47, 48, 49, and 50 illustrate a processflow which may be used to fabricate a multi-layer capacitor, such as themulti-layer capacitor of FIGS. 37/38, according to some embodiments;

FIG. 51 illustrates a heat dissipation method using a MEMS/NEMS devicehaving integrated decoupling capacitors, according to some embodiments;

FIGS. 52, 53, 54, 55, 56, 57, and 58 illustrate the structure andoperation of various embodiments of a MEMS/NEMS device useful forimplementing a dual electrostatic forces (e.g., dual eForces)I-MEMS/I-NEMS structure;

FIGS. 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74,75, and 76 illustrate a process flow which may be used to fabricate dualeForces MEMS/NEMS devices and/or circuits; and

DETAILED DESCRIPTION

The following discussion is directed to various embodiments whichprovide a method, a device, and a system for controlling power to anintegrated circuit (IC) device. Although one or more of theseembodiments may be preferred, the embodiments disclosed should not beinterpreted, or otherwise used, as limiting the scope of the disclosure,including the claims, unless otherwise specified. In addition, oneskilled in the art will understand that the following description hasbroad application, and the discussion of any embodiment is meant only tobe exemplary of that embodiment, and not intended to intimate that thescope of the disclosure, including the claims, is limited to thatembodiment. Also, layers and/or elements depicted herein are illustratedwith particular dimensions and/or orientations relative to one anotherfor purposes of simplicity and ease of understanding, and actualdimensions and/or orientations of the layers and/or elements may differsubstantially from that illustrated herein.

Certain terms are used throughout the following description and claimsto refer to particular system components. As one skilled in the art willappreciate, various companies may refer to a component by differentnames. This document does not intend to distinguish between componentsthat differ in name but not function. In the following discussion and inthe claims, the terms “including” and “comprising” are used in anopen-ended fashion, and thus should be interpreted to mean “including,but not limited to . . . ”. Also, the term “couple” or “couples” isintended to mean either an indirect or direct connection. Thus, if afirst device couples to a second device, that connection may be througha direct connection, or through an indirect connection via other devicesand connections. Unless otherwise stated, when a layer is said to be“deposited over the substrate” or “formed over the substrate”, it meansthat the layer is deposited or formed over any topography that alreadyexists on the substrate.

The subject matter disclosed herein is directed to methods associatedwith formation of an electromechanical power switch (e.g., a MEMS-and/or NEMS-based switch), which in some cases may be used as adecoupling capacitor and/or used in tandem with another MEMS/NEMS switchthat is used as a decoupling capacitor. Such switches and decouplingcapacitors may be used for controlling power to an IC device, such as acomplementary metal-oxide-semiconductor (CMOS) device, a bipolar-CMOS(BiCMOS) device, an n-type MOS (NMOS) device, a p-type (PMOS) device,and more generally for controlling power to any of a plurality ofcircuit blocks including at least one of the above-mentioned IC devices,such as a logic circuit, a central processing unit (CPU), a graphicsprocessing unit (GPU), a microcontroller unit (MCU), a radio frequency(RF) circuit, an analog circuit, a memory, a memory controller, and aninput/output (I/O) interface, among others. As used herein, the term“controlling power” (e.g., to an IC device and/or circuit block) isequivalently used to mean “gating a voltage supply” (e.g., to an ICdevice and/or circuit block). Thus, for example, an electromechanicalswitch that controls power to an IC device and/or circuit block isunderstood equivalently as an electromechanical switch that gates avoltage supply to the IC device and/or circuit block.

The potential performance gains afforded by MEMS/NEMS devices, includingnear infinite OFF state resistance, low ON state resistance afforded byohmic metal-metal contacts, and the increased device density due tosmall device footprints have continued to drive significant interest inCMOS-MEMS/NEMS integration. Various CMOS-MEMS/NEMS integration schemeshave been reported, including a hybrid fabrication approach as well as avariety of monolithic (i.e., single substrate) approaches. In the hybridapproach, CMOS and MEMS/NEMS ICs are each fabricated separately andbonded, and electrical connections between the two ICs are then made.The hybrid approach suffers from high assembly and packaging costs, aswell as significant performance-limiting parasitic resistance, largelydue to bond pads and bonding wires used for the interconnection betweenthe separate CMOS and MEM/NEMS ICs. Moreover, using separate substratesfor each of the CMOS and MEMS/NEMS ICs makes it very challenging toincrease device density. Monolithic integration of CMOS and MEMS/NEMSICs can improve overall device performance, for example, by reducingparasitic resistance, among others. Monolithic integration can alsoimprove on-chip device density. Exemplary methods of monolithicintegration include formation of CMOS devices using standardsemiconductor processing techniques, followed by formation of a MEMSstructure. However, the monolithic integration schemes studied thus farhave largely been narrowly focused on specific types of MEMS devices(e.g., high aspect ratio MEMS devices, MEMS inertial sensors, etc.).Moreover, with regards to power gating techniques, the IC industry stillheavily relies on leaky MOS-based power gates. Thus, an improved powergating method utilizing an electromechanical power gate (e.g., a MEMSand/or NEMS-based power gate) for controlling power to any of aplurality of circuit blocks is needed. Moreover, methods and devices forensuring signal integrity (e.g., in a power distribution system) arealso needed, and are addressed by embodiments of the present disclosure,as described below.

As illustrated in FIG. 1, a power switch can be used to implement apower gating technique, wherein the standby consumed power is reduced byusing power gating transistors to switch off inactive or non-operationalIC devices or circuitry. Further, as traditional MOS-based power gatessuffer from significant power consumption due to the OFF state leakageof the MOS device, there is a need for an alternative power gatingtechnique that does not rely on leaky MOS-based power gates. Such analternative exists in the form of using an electromechanical switch asthe power gate, as illustrated in FIG. 2A. The structure of theelectromechanical switch of FIG. 2A, as well as the methods of makingand using the electromechanical switch, are described in U.S. patentapplication Ser. No. 13/975,216, entitled “METHOD OF FORMING ANELECTROMECHANICAL POWER SWITCH FOR CONTROLLING POWER TO INTEGRATEDCIRCUIT DEVICES AND RELATED DEVICES”, filed Aug. 23, 2013, now U.S. Pat.No. 8,786,130, the entire disclosure of which is incorporated herein byreference.

By way of example, the electromechanical switch 202 may be coupled to acircuit block 204, where the electromechanical switch 202 and thecircuit block 204 are monolithically integrated on the same substrate.Moreover, the electromechanical switch 202 controls the power suppliedto the circuit block 204 from the voltage supply (V_(DD)) by way of agate control signal at an input of the electromechanical switch 202. Invarious embodiments, the circuit block 204 includes at least one of alogic circuit, a CPU, a GPU, an MCU, an RF circuit, an analog circuit, amemory, a memory controller, an I/O interface, a cache, a networkinterface, and/or subsystems of these devices/circuits. In otherembodiments, the circuit block 204 includes any of a plurality of ICdevices, such as a CMOS device, a BiCMOS device, an NMOS device, and/ora PMOS device, a logic circuit, a CPU, a GPU, an MCU, an RF circuit, ananalog circuit, a memory, a memory controller, an I/O interface, acache, a network interface, a very large scale integration (VLSI) chip,an ultra large scale integration (ULSI) chip, or a system-on-a-chip(SOC), among others. The electromechanical switch 202 operates byactuation of a cantilever to close an air gap and provide contactbetween two metal electrodes. For purposes of this disclosure, the terms“electromechanical switch” or “electromechanical power gate” are meantto include MEMS-based switches and MEMS-based power gates, as well asNEMS-based switches and NEMS-based power gates. In an exemplary example,when the gate control signal is activated, the electromechanical switch202 is ON, causing the two metal electrodes of the electromechanicalswitch 202 to contact one another, and a virtual V_(DD) coupled to thecircuit block 204 is approximately equal to V_(DD). When in contact, thetwo metal electrodes provide a very low-resistance contact whichminimizes parasitic voltage drop across the electromechanical switch202. In an alternative embodiment, when the gate control signal is notactivated, the electromechanical switch 202 is OFF, and the virtualV_(DD) is zero. Moreover, when the electromechanical switch is in an OFFstate, an air gap between the two metal electrodes provides a nearinfinite OFF-state resistance and thus essentially zero OFF-statecurrent, which is unachievable with MOS devices, and thus completelyturning off of the power supplied to the circuit block 204. While theexample of FIG. 2A shows the electromechanical switch 202 between thecircuit block 204 and the power network (V_(DD)), the electromechanicalswitch 202 could also be coupled between the circuit block 204 and aground connection (V_(SS)).

As discussed above, electromechanical power switches (e.g., FIG. 2A) canbe used to implement a power gating technique, and thus may be part of apower distribution system (PDS). In general, a power distribution system(PDS) may be used to supply/distribute power (e.g., via one or morepower supplies) across internal connections of an integrated circuit(IC), through an IC package, through a printed circuit board (PCB),through a backplane, and/or through inter-system connections, amongothers. A key consideration of any PDS is signal integrity (i.e., thequality of an electrical signal, such as a power supply signal). In someexamples, inadequate signal integrity of a PDS may lead to degradeddevice and/or circuit performance, as well as device and/or circuitfailure. At least some methods of achieving signal integrity include theuse of decoupling capacitors (e.g., in a PDS system). In variousexamples, decoupling capacitors may be used to reduce switching noise inthe PDS. In some cases, noise caused by other circuit elements may beshunted through a decoupling capacitor, reducing the effect of the noiseon the IC. Decoupling capacitors may be used to reduce noise from any ofa variety of sources. For example, in a radio frequency (RF) circuit,electrical noise may be generated by oscillators, amplifier circuits,and/or other circuit elements as known in the art. In a digital circuitenvironment, electrical noise may be generated by switching (e.g.,including power gate switching), by power supplies, and by regulators,among others. In digital ICs, for example, electrical noise may lead todetection of a false-high and/or false-low signal, as well as voltagedroop, resistive/inductive delays, as well as other issues as known inthe art. Methods for achieving signal integrity, including the use ofdecoupling capacitors, can be used to reduce such electrical noise andprovide clean logic states (i.e., clean logic ‘0’ and logic ‘1’ states).In some examples, electrical noise may be viewed as a voltage ripple (orvoltage drop across an ideal capacitor), at a given current ‘I’, wheresuch a ripple voltage may be defined by the equation: V=I/ωC. Thus, to afirst-order, an increase in capacitance ‘C’ (e.g., provided by adecoupling capacitor) will result in a reduction in the ripple voltagewhen an IC device draws current. Additional discussion related todecoupling capacitors is provided in the publication by Yun Chaseentitled “Introduction to Choosing MLC Capacitors for Bypass/DecouplingApplications”, AVX Corporation, Datasheet S-ITCMLC2.5M201-N, 2004, theentirety of which is incorporated herein by reference.

With reference now to FIG. 2B, illustrated therein is a circuit block203 including an electromechanical switch 205, and integrated decouplingcapacitors 207, that may be coupled to the circuit block 204, where thecircuit block 203 and the circuit block 204 are monolithicallyintegrated on the same substrate. Similar to the example of FIG. 2A, theelectromechanical switch 205 of the circuit block 203 (shown in FIG. 2B)may control the power supplied to the circuit block 204 from the voltagesupply (V_(DD)) by way of a gate control signal at an input of theelectromechanical switch 205, while also reducing electrical noise andproviding improved signal integrity by use of the integrated decouplingcapacitors 207. In at least some embodiments, the electromechanicalswitch 205 may operate similarly to the electromechanical switch 202, asdiscussed above. In some embodiments, the electromechanical power switch205 may itself be used alternately as either a power switch or as adecoupling capacitor. In some cases, one or both of the integrateddecoupling capacitors 207 may be used alternately as either a powerswitch or as a decoupling capacitor. In some examples, one or both ofthe integrated decoupling capacitors 207 may include dedicateddecoupling capacitors to be used in tandem with electromechanical switch205. While the example of FIG. 2B shows the circuit block 203 betweenthe circuit block 204 and the power network (V_(DD)), the circuit block203 could also be coupled between the circuit block 204 and a groundconnection (V_(SS)).

Expanding on the example of FIG. 2B, FIG. 2C illustrates a system 250which shows an embodiment where a circuit block 206, including anelectromechanical switch and decoupling capacitor(s), is coupled to anIC device 208, where the circuit block 206 and the IC device 208 aremonolithically integrated on the same substrate. Moreover, the circuitblock 206 controls the power supplied to the IC device 208 from a powersupply 210 by way of a gate control signal at an input of theelectromechanical switch of the circuit block 206, while the decouplingcapacitors of the circuit block 206 reduce electrical noise. In variousembodiments, the IC device 208 includes at least one of a logic circuit,a CPU, a GPU, an MCU, an RF circuit, an analog circuit, a memory, amemory controller, an I/O interface, a cache, a network interface,and/or subsystems of these devices/circuits. In other embodiments, theIC device 208 includes any of a plurality of IC devices, such as a CMOSdevice, a BiCMOS device, an NMOS device, and/or a PMOS device, amongothers. Furthermore, the IC device 208 may include a very large scaleintegration (VLSI) chip, an ultra large scale integration (ULSI) chip,or a system-on-a-chip (SOC), among others. Moreover, the circuit block206 may be coupled to a plurality of circuit blocks 212, 214 within theIC device 208, wherein each of the circuit blocks 212, 214 may alsoinclude an electromechanical switch and decoupling capacitor(s), andwhere circuit block 212 is coupled to a circuit block 216 and circuitblock 214 is coupled to a circuit block 218. The circuit block 212 maycontrol the power supplied to the circuit block 216 from the voltagesupply (V_(DD)) by way of a gate control signal at an input of theelectromechanical switch of the circuit block 212, while the decouplingcapacitors of the circuit block 212 reduce electrical noise. Likewise,the circuit block 214 may control the power supplied to the circuitblock 218 from the voltage supply (V_(DD)) by way of a gate controlsignal at an input of the electromechanical switch of the circuit block214, while the decoupling capacitors of the circuit block 214 reduceelectrical noise. Thus, as shown in FIG. 2C, each of the plurality ofelectromechanical switches of the circuit blocks 212, 214 may controlthe power supplied to individual circuit blocks within the IC device208, and the electromechanical switch of the circuit block 206 maycontrol the power supplied to the overall IC device 208. While theexample of FIG. 2C discusses embodiments where the circuit block 206 andthe IC device 208 are monolithically integrated on the same substrate,those skilled in the art will recognize that some embodiments, forexample using the hybrid approach, may be implemented where the circuitblock 206 and the IC device 208 are each fabricated separately andbonded, and electrical connections between the circuit block 206 and theIC device 208 are subsequently made.

FIG. 3 depicts a schematic representation of an exemplary CPU/GPU powermanagement system 300, which may be part of a data processing system asdescribed below with reference to FIG. 4, and which is useful forimplementing MEMS/NEMS-based power gating, while using integrateddecoupling capacitors. In some embodiments, the power management system300 may be a power distribution system (PDS) and/or may form part of aPDS. The CPU/GPU power management system 300 may include a plurality ofCPU/GPU cores 318, 320, 322, 324. CPU/GPU cores 318, 320 are coupled toL2 cache 326, and CPU/GPU cores 322, 324 are coupled to L2 cache 328.Each of the CPU/GPU cores 318, 320, 322, 324 may communicate with anexternal computer and/or data processing system by way of a system bus304. As shown in FIG. 3, a voltage supply V_(DD) connects to each of theCPU/GPU cores and L2 caches through a MEMS/NEMS-based electromechanicalswitch. More specifically, the voltage supply V_(DD) connects to each ofthe CPU/GPU cores and L2 caches through a circuit block that includesboth a MEMS/NEMS-based electromechanical switch as well as one or moredecoupling capacitors. For example, a circuit block 306 (including anelectromechanical switch and decoupling capacitors) is coupled to the L2cache 326, a circuit block 308 (including an electromechanical switchand decoupling capacitors) is coupled to the CPU/GPU core 318, a circuitblock 310 (including an electromechanical switch and decouplingcapacitors) is coupled to the CPU/GPU core 320, a circuit block 312(including an electromechanical switch and decoupling capacitors) iscoupled to the L2 cache 328, a circuit block 314 (including anelectromechanical switch and decoupling capacitors) is coupled to theCPU/GPU core 322, and a circuit block 316 (including anelectromechanical switch and decoupling capacitors) is coupled to theCPU/GPU core 324.

In various embodiments, at least one of the circuit blocks 306, 308,310, 312, 314, 316 is monolithically integrated on the same substrate asthe CPU/GPU core and/or L2 cache to which it is coupled. In someembodiments, activation (i.e., actuation) of each of theelectromechanical switches within each of the circuit blocks 306, 308,310, 312, 314, 316 may be controlled by a power management unit 302. Insome embodiments, the power management unit 302 includes a power switchcircuit. The power switch circuit may include any of a plurality of ICdevices, such as CMOS, BiCMOS, NMOS, and/or PMOS devices, among others.Further, in some embodiments, the power switch circuit may bemonolithically integrated on the same substrate as the electromechanicalswitch and/or circuit block to which it is coupled. In variousembodiments, power consumption within the CPU/GPU power managementsystem 300 can be reduced by shutting off power to one or more of theCPU/GPU cores and/or L2 caches, for example, during periods ofinactivity and/or non-operation. Illustratively, in response to a signalfrom the power management unit 302, one or more of the electromechanicalswitches within the circuit blocks 306, 308, 310, 312, 314, 316 may beactuated in such a way so as to turn off power to one or more of theCPU/GPU cores and/or L2 caches. In some embodiments, an entire CPU/GPUcore is shut off by way of one of the electromechanical switches withinthe circuit blocks 306, 308, 310, 312, 314, 316. In other embodiments,at least one CPU/GPU core internal component, such as an arithmeticlogic unit (ALU), a control unit (CU), and/or a register, is shut off byway of one of the electromechanical switches within the circuit blocks306, 308, 310, 312, 314, 316.

In the various examples discussed above, in addition to controlling avoltage supply to one or more of the CPU/GPU cores and/or L2 caches byway of the electromechanical switches within the circuit blocks to whichthey are connected, the decoupling capacitors within each of therespective circuit blocks may simultaneously be effectively employed toreduce electrical noise. Additionally, for example in embodiments whereone or both of the integrated decoupling capacitors within the circuitblocks 306, 308, 310, 312, 314, 316 are capable of being usedalternately as either a power switch or as a decoupling capacitor, theselected configuration (i.e., either decoupling capacitor or powerswitch) may be selected in response to a signal received by the powermanagement unit 302. While FIG. 3 shows each of the circuit blocks 306,308, 310, 312, 314, 316 coupled between the voltage supply V_(DD) andone of the CPU/GPU cores or L2 caches, one or more of the circuit blocks306, 308, 310, 312, 314, 316 could instead be coupled between a groundconnection (not shown) and one of the CPU/GPU cores or L2 caches.

Expanding the discussion as related to FIG. 3, FIG. 4 illustrates ablock diagram representation of an example data processing system (DPS)400, as utilized within some embodiments. The DPS 400 is useful forimplementing MEMS/NEMS-based power gating, for example while usingintegrated decoupling capacitors, where power to one or more DPS circuitblocks is controlled by a MEMS/NEMS device (that may be used in tandemwith one or more decoupling capacitors) and a power management unit, asdescribed below. As used herein, the term “data processing system,” isintended to include any type of computing device or machine that iscapable of receiving, storing and running a software product includingnot only computer systems, but also devices such as communicationdevices (e.g., routers, switches, pagers, telephones, electronic books,electronic magazines and newspapers, etc.) and personal and homeconsumer devices (e.g., handheld computers, Web-enabled televisions,home automation systems, multimedia viewing systems, etc.).

As shown in FIG. 4, a DPS 400 may comprise a CPU/GPU 422 including aMEMS/NEMS circuit block 431, a system memory 426 including a MEMS/NEMScircuit block 425, where the system memory 426 is coupled to a memorycontroller 428 which includes a MEMS/NEMS circuit block 427, and asystem interconnect 430 that couples the memory controller 428 to theCPU/GPU 422 and other components of the DPS 400. In various embodiments,each of the MEMS/NEMS circuit blocks 431, 425, 427 may include one ormore electromechanical switches and one or more decoupling capacitors,as described above. The system interconnect 430 in an embodiment can bean address and data bus. Commands on the system interconnect 430 arecommunicated to various system components under the control of a busarbiter 432.

The DPS 400 can further include cache memory 423 for high speed storageof frequently used data. The cache memory 423 can be connected to orcommunicatively coupled to the CPU/GPU 422. While the cache memory 423is shown operatively connected to the CPU/GPU 422, the cache memory 423can also operatively be a part of the system memory 426.

The DPS 400 further includes computer readable storage media, such asone or more multimedia drives 438, including for example hard diskdrives. Multimedia drives 438 provide non-volatile storage for the DPS400. The DPS 400 also includes one or more user interface devices, whichallow a user to provide input and receive output from the DPS 400. Forexample, user interface devices can include displays 434, keyboards 440,universal serial bus (USB) ports 436, and pointing devices such as amouse 442. The multimedia drives 438 and the various user interfacedevices can be communicatively coupled to the system interconnect 430 byan I/O interface 435 which includes a MEMS/NEMS circuit block 429. Insome embodiments, the MEMS/NEMS circuit block 429 may also include oneor more electromechanical switches and one or more decouplingcapacitors, as described above. Although the description of computerreadable storage media above refers primarily to a hard disk, it shouldbe appreciated by those skilled in the art that other types of mediawhich are readable by a computer, such as removable magnetic disks,CD-ROM disks, magnetic cassettes, flash memory cards, digital videodisks, Bernoulli cartridges, and other later-developed hardware, mayalso be used in the exemplary computer operating environment.

In some embodiments, actuation of electromechanical switches within eachof the MEMS/NEMS circuit blocks 425, 427, 429, 431 may be controlled bya power management unit (PMU) 452, which is communicatively coupled toeach of the MEMS/NEMS circuits blocks 425, 427, 429, 431 by way of thesystem interconnect 430. In some embodiments, the power management unit452 includes a power switch circuit. The power switch circuit mayinclude any of a plurality of IC devices, such as CMOS, BiCMOS, NMOS,and/or PMOS devices, among others. Moreover, each of theelectromechanical switches of each of the MEMS/NEMS circuit blocks 425,427, 429, 431 may be used to control power grid connectivity of thecircuit blocks to which each of the electromechanical switches arecoupled, for example, to reduce power consumption during periods ofinactivity and/or non-operation. At the same time, each of the one ormore decoupling capacitors within each of the MEMS/NEMS circuit blocks425, 427, 429, 431 may be used to reduce electrical noise to betweeneach of the MEMS/NEMS circuit blocks 425, 427, 429, 431 and the DPS 400circuit blocks to which each of the MEMS/NEMS circuit blocks 425, 427,429, 431 are coupled. For example, the electromechanical switch of theMEMS/NEMS circuit block 425 can be used to control power to the systemmemory 426, while the decoupling capacitors of the MEMS/NEMS circuitblock 425 reduce electrical noise. Similarly, the electromechanicalswitch of the MEMS/NEMS circuit block 427 can be used to control powerto the memory controller 428, while the decoupling capacitors of theMEMS/NEMS circuit block 427 reduce electrical noise. Likewise, theelectromechanical switch of the MEMS/NEMS circuit block 429 can be usedto control power to the I/O interface 435, while the decouplingcapacitors of the MEMS/NEMS circuit block 429 reduce electrical noise.Also, the electromechanical switch of the MEMS/NEMS circuit block 431can be used to control power to the CPU/GPU 422 as well as to the cachememory 423, as discussed with reference to FIG. 3, while the decouplingcapacitors of the MEMS/NEMS circuit block 431 reduce electrical noise.In some embodiments, the entire CPU/GPU 422 may be shut off by way ofthe electromechanical switch of the MEMS/NEMS circuit block 431. Inother embodiments, at least one CPU/GPU internal component, such as anALU, a CU, and/or a register, is shut off by way of theelectromechanical switch of the MEMS/NEMS circuit block 431.Illustratively, in response to a signal from the power management unit452, one or more of the electromechanical switches within the MEMS/NEMScircuit blocks 425, 427, 429, 431 may be actuated in such a way so as toturn off power to one or more of the system memory 426, the memorycontroller 428, the I/O interface 435, and the CPU/GPU 422.Additionally, for example in embodiments where one or more of theintegrated decoupling capacitors within the MEMS/NEMS circuit blocks425, 427, 429, 431 are capable of being used alternately as either apower switch or as a decoupling capacitor, the selected configuration(i.e., either decoupling capacitor or power switch) may be selected inresponse to a signal received by the power management unit 452. Whilethe description of FIG. 4 has described using a MEMS/NEMS-based powergating technique, with integrated decoupling capacitors, for a specificsubset of circuit blocks of the DPS 400, namely the system memory 426,the memory controller 428, the I/O interface 435, and the CPU/GPU 422,it will be appreciated that power supplied to other functional blockswithin the DPS 400, such as for example the bus arbiter 432, the networkinterface 444, and each of the I/O devices including the display 434,the USB port 436, the multimedia drive 438, the keyboard 440, and themouse 442, may similarly be controlled by using a MEMS/NEMS-based powergating technique and utilizing integrated coupling capacitors, asdescribed herein.

The DPS 400 may also operate in a networked environment using logicalconnections to one or more remote computers or hosts, such as a DPS 402.The DPS 402 may be a computer, a server, a router or a peer device andtypically includes many or all of the elements described relative to theDPS 400. In a networked environment, program modules employed by the DPS400, or portions thereof, may be stored in a remote memory storagedevice 450. The logical connections depicted in FIG. 4 can includeconnections over a network 441. In one embodiment, the network 441 maybe a local area network (LAN). In alternative embodiments, the network441 may include a wide area network (WAN). The DPS 400 is connected tothe network 441 through an input/output interface, such as a networkinterface 444. It will be appreciated that the network connections shownare exemplary and other means of establishing a communications linkbetween the computers may be used.

The electromechanical switches and integrated decoupling capacitors usedto implement the various MEMS/NEMS-based power gating embodiments asshown in FIGS. 2B, 2C, 3, and 4 can be monolithically integrated withany of a plurality of circuit blocks in accordance with a variety ofmethods, as discussed below, using standard semiconductor processingtechniques, such as for example, photolithography, etching processes(e.g., wet, dry, and/or plasma etching), deposition processes, and/orother standard processes. Moreover, the electromechanical switches anddecoupling capacitors discussed herein may include a plurality ofconfigurations, structural features, and materials such as metal,polycrystalline silicon (poly-Si), dielectrics, and/or other materialswell known in the art. For example, in some embodiments, theelectromechanical switches may include a vertical structure, where aMEMS/NEMS structural layer (e.g., a cantilever) is actuated in avertical direction. In other embodiments, the electromechanical switchesmay include a lateral structure, where the MEMS/NEMS structural layer isactuated in a horizontal direction. In some embodiments, the decouplingcapacitors may include MEMS/NEMS devices configured to operate asdecoupling capacitors, as discussed below. In some cases, the decouplingcapacitors may include dedicated decoupling capacitors used in tandemwith one or more MEMS/NEMS electromechanical switches. The discussion ofspecific processes, configurations, structural features, and/ormaterials used in the formation of the electromechanical switches anddecoupling capacitors discussed herein is not meant to be limiting, andthe choice of specific processes, device configurations, structuralfeatures, and/or materials may vary depending, for example, on the typeof MEMS, NEMS, and/or capacitor device that is desired.

In addition to the advantages discussed above, further advantages andbenefits of embodiments of the present disclosure will become apparentto those skilled in the art upon reading the discussion that follows,including the description of FIGS. 5-33 below. For example, withreference to FIG. 5, illustrated therein is a schematic diagram of afour-terminal (4T) electromechanical switch, as well as cross-sectiondiagrams illustrating the operation of the 4T switch. In someembodiments, such a 4T electromechanical structure is employed (e.g., asopposed to a 3-terminal structure) in order to reduce an operationvoltage (e.g., threshold voltage, V_(TH)) of the electromechanicalswitch. As illustrated in FIG. 5, when the device is OFF (i.e., when agate-to-body voltage V_(GB) is less than V_(TH)), an air gap separates adevice channel from the source and drain, ensuring no current flow. Asfurther illustrated in FIG. 5, when the device is ON (i.e., when V_(GB)is equal to or greater than V_(TH)), an electrostatic force causes thegate to be deflected downward such that the channel comes into contactwith the source/drain electrodes, thereby providing a conductive currentpath. As also shown in FIG. 5, and in some embodiments of the presentdisclosure, the gate may include a folded-flexure design (e.g., aspring-like design) in order to relieve residual stress within the gate.

Of particular interest, FIG. 5 also shows the gate electrode overlappingthe body. In operation, consider an example where the body voltage V_(B)is equal to the supply voltage V_(DD) and the gate voltage V_(G) isequal to zero. In such a biasing configuration, the gate (and conductivechannel) may be pulled down to contact the source/drain, thereby turningthe device ON. However, consider also that the drain voltage V_(D) isalso equal to V_(DD), and thus when the device is ON, the voltage of thechannel may be substantially equal to the body voltage V_(B). In thiscase, and in particular due to the overlap between the gate electrodeand the body, the gate (and conductive channel) may inadvertently bepushed up away from the source/drain contacts, thereby turning thedevice OFF when it should be ON. By way of example, such behavior (e.g.,due to the overlap between the gate electrode and the body) may bereferred to as being caused by parasitic electrostatic forces.

In addition, still referring to FIG. 5, when the device is intentionallyswitched OFF (e.g., V_(G) is equal to V_(B)), the gate (and conductivechannel) are forced upward by the spring force of the electromechanicaldevice. However, due to stiction (i.e., static friction forces), thesurfaces along which the conductive channel contacts the source/drainelectrodes may become inadvertently stuck to one another (i.e., they maynot disconnect), thereby causing the device to remain ON when it shouldbe OFF. Also, as discussed above, different electromechanical switchdevices may be used for a variety of different circuit blocks. In somecases, actuating a particular electromechanical switch (e.g., belongingto a first circuit block) ON or OFF, may cause electrical noise and/orelectrical spikes in the power lines of other circuit blocks.

Thus, embodiments of the present disclosure provide methods, devices,and systems for overcoming the shortcomings of existing solutions,including those problems discussed in relation to FIG. 5. For example,embodiments of the present disclosure provide electromechanical switchdevices where the gate electrode (and conductive channel) do not overlapthe body, thereby avoiding the effect of the parasitic electrostaticforces discussed above. In addition, embodiments of the presentdisclosure provide methods and devices including MEMS/NEMS integrateddecoupling capacitors to reduce electrical noise, as discussed above. Insome embodiments, an integrated MEMS/NEMS device may be convertedbetween functioning as a power gate and a decoupling capacitor. Otherembodiments include using redundant integrated MEMS/NEMS devices toserve as redundant power gates. In other embodiments, a plurality ofintegrated MEMS/NEMS devices may be used to enable a multi-power supplyMEMS/NEMS switch. In some examples, such multi-supply MEMS/NEMS switchesmay be alternately used as decoupling capacitors and/or combined withadditional MEMS/NEMS devices used as decoupling capacitors. In someembodiments, embodiments integrate MEMS/NEMS devices may be used toenable an anti-stiction switching method as well as a 3-D decouplingcapacitor, as discussed below. It is understood that embodiments of thepresent disclosure offer advantages over the existing art, and variousembodiments may offer different advantages; however, not all advantagesare necessarily discussed herein, and no particular advantage isrequired for all embodiments. One of ordinary skill in the art inpossession of this disclosure will appreciate that the methods andstructures described herein may be equally applicable to other types ofdevices without departing from the scope of the present disclosure.Moreover, other embodiments and advantages will be evident to thoseskilled in the art upon reading the present disclosure.

With reference to the discussion below, first some of the variousembodiments (e.g., various devices, circuits, structures, etc.) of thepresent disclosure will be discussed with reference to FIGS. 6A, 6B, 6C,6D, 7, 8A-8B, 9A-9B, 10A-10B, 11A-11B, 12, 13A-13B, 14A-14B, 15A-15B,and 16A-16B. Thereafter, a discussion of methods of fabrication, relateddevices, and other aspects of the present disclosure will be given withreference to FIGS. 17-33. While certain examples are discussed hereinfor purposes of understanding the various aspects of the presentdisclosure, those skilled in the art will readily appreciate that thepresent embodiments are not limited by those examples, and that themethods, devices, circuits, structures, etc. may be modified and/oraltered in various ways without departing from the scope and spirit ofthe present disclosure.

Referring now to the examples of FIGS. 6A, 6B, 6C, and 6D, illustratedtherein is an embodiment of a MEMS/NEMS device having integrateddecoupling capacitors. In the various embodiments described herein, theMEMS/NEMS device and decoupling capacitors may be monolithicallyintegrated on a substrate including one or more IC devices. In someexamples, at least some of the monolithic integration processesdescribed herein may be similar to that described in U.S. Pat. No.8,786,130, which as discussed above, is incorporated herein by referencein its entirety.

FIG. 6A shows a top-view of a device 600 including anembedded/integrated electromechanical power switch (e.g., MEMS/NEMSdevice) 605 including a source 609, a drain 611, a body 613, and a gate615. As discussed above, in some embodiments, the gate 615 may include afolded-flexure design (e.g., a spring-like design) in order to relieveresidual stress within the gate 615. Anchors/contacts 619 to the gate615 are also shown. As shown, the device 600 also includes a pluralityof integrated decoupling capacitors 621, 623, which are described inmore detail below. In addition, in various embodiments, the body 613 mayinclude a discontinuity (e.g., as shown underneath the gate 615) havinga spacing ‘S’, where at least part of a conductive channel switchingmetal 617, coupled to the gate 615 (e.g., with a dielectric interposedtherebetween), is disposed to pass through the spacing ‘S’ of the body613 discontinuity and is configured to have a width ‘Wc’ that is lessthan the spacing ‘S’ of the body 613 discontinuity. Thus, there is nooverlap between the gate electrode (conductive channel) and the body,and parasitic electrostatic forces are thereby avoided. In someexamples, such a design may be referred to as a “split-body” design.

In some embodiments, the electromechanical power switch 605 may beformed within an area defined by a DPS circuit block 607 in accordancewith some embodiments. For example, in some embodiments at least oneelectromechanical power switch, such as the electromechanical powerswitch 605, and at least one circuit block, such as the circuit block607, to which the electromechanical power switch 605 is coupled, areformed within an area on a front surface of a semiconductor substrate.In various embodiments, the area on the front surface of thesemiconductor substrate is defined by an area bounded by the circuitblock 607. Additionally, in some embodiments, an array of embeddedelectromechanical power switches (e.g., such as the switch 605) may beformed within a DPS. In various examples, any number of a plurality ofelectromechanical switches may be formed throughout the DPS, andformation of such a plurality of electromechanical switches is notconstrained to an area defined by a DPS circuit block, as discussedabove.

FIG. 6B shows a cross-section view of the device 600, along section AA′of FIG. 6A, showing the switch 605 and the decoupling capacitors 621,623 formed over a semiconductor substrate 630. In various embodiments,any of a plurality of IC devices may be formed within an IC device layerof the semiconductor substrate 630, according to standard semiconductorprocessing techniques. In some embodiments, the semiconductor substrate630 includes a silicon (Si) substrate. In other embodiments, thesemiconductor substrate 630 may include, for example, a germanium (Ge)substrate, a silicon-germanium (SiGe) substrate, a silicon-on-insulator(SOI) substrate, a silicon carbide (SiC) substrate, a gallium arsenide(GaAs) substrate, an indium arsenide (InAs) substrate, an indium galliumarsenide (InGaAs) substrate, an indium phosphide (InP), or anothersubstrate as well known in the art. The IC devices formed within the ICdevice layer of the semiconductor substrate 630 may include anycombination of a CMOS device, a BiCMOS device, an NMOS device, and/or aPMOS device, among others. Moreover, in some embodiments, at least someof the IC devices formed within the IC device layer of the substrate 630may form a power switch circuit useful for controlling power to any of aplurality of circuit blocks, where at least some of the IC deviceswithin the IC device layer of the substrate 630 may form circuit blockssuch as a logic circuit, a CPU, a GPU, an MCU, an RF circuit, an analogcircuit, a memory, a memory controller, and/or an I/O interface, amongothers. In some embodiments, the IC devices may be stacked within the ICdevice layer of the substrate 630.

In some embodiments, the formation of an embedded electromechanicalpower switch 605 and the decoupling capacitors 621, 623 includes theformation of a dielectric layer over the semiconductor substrate 630,for example to electrically isolate and/or protect IC devices within thesubstrate from the materials (e.g., metal) used to fabricate the switch605 and the decoupling capacitors 621, 623. However, it will beunderstood that openings may be formed in such an isolating dielectriclayer (e.g., by a patterning and etching process) in order to connectmetal layers above the isolating dielectric layer to devices, circuits,and/or other metal layers or interconnects below the isolatingdielectric layer. In various embodiments, such an insulating dielectriclayer formed over the substrate 630 may include a silicon nitride layer,such as a plasma-enhanced chemical vapor deposition (PECVD) siliconnitride layer, a low-K backend dielectric, or other dielectric as knownin the art. As shown in FIG. 6B, the device 600 includes a dielectriclayer 632, the source 609, and the drain 611. In some examples, thedielectric 632 may include the isolating dielectric described above. Insome embodiments, the dielectric 632 includes a back-end low-Kdielectric material. In various embodiments, each of the source anddrain 609, 611 may include a metal material such as copper; howeverother metals known in the art may be used as well. The metal materialused to form the source and drain 609, 611 may be isolated from thesubstrate 630 by the insulating dielectric formed over the substrate630, as described above.

Each of the decoupling capacitors 621, 623 may include a dielectriclayer 636 over the source/drain 609, 611 a metal layer 638 over thedielectric layer 636, a dielectric layer 634 over the metal layer 638,and an electrode 640 over the dielectric layer 634. In some embodiments,the MEMS/NEMS switch 605 includes the conductive channel switching metal617, a dielectric layer 634 over the switching metal 617, and a gateelectrode 641 over the dielectric layer 634. In some embodiments, theswitch 605 includes a mechanical structure, such as a cantilever, usedto alternately open/close an air gap between at least two electrodes(e.g., which make electrical contact between ends of the switching metal617 and each of the source and drain 609, 611) and alternately provide avery low-resistance contact or a near-infinite resistance contact. Inaddition, while the decoupling capacitors 621, 623 are shown as staticcapacitor structures, in some embodiments, one or both of the decouplingcapacitors 621, 623 may be implemented as switches (similar to theswitch 605) but may be configured to act as capacitors (e.g., inresponse to a signal received from the power management unit). Forexample, in a case where one or both of the decoupling capacitors 621,623 are implemented as switches, the power management unit may configureone or both of the decoupling capacitors 621, 623 to remain in a closed(actuated) position and thus act as a capacitor (e.g., when usingstructure similar to the switch 605 to act as a capacitor, when theswitch is closed, an air gap may serve as the capacitor dielectric).

Formation of the MEMS/NEMS switch 605, as well as each of the decouplingcapacitors 621, 623, may include any of a plurality of processing steps,such as material deposition, photolithography to define patterns in thedeposited layers, and etching processes to further define the patternedlayers and release the at least one mechanical structure of theMEMS/NEMS structural layer. Such processing steps are described in moredetail below, for example, with reference to FIGS. 19-24. In someembodiments, the device 600 may be capped by an encapsulation layer,such as a PECVD thin film layer, a silicon nitride layer, an oxidelayer, and/or a combination of the two, among others.

FIG. 6C shows a cross-section view of the device 600, along section BB′of FIG. 6A, showing the switch 605 and the decoupling capacitors 621,623 formed over a semiconductor substrate 630. As shown in FIG. 6A,section BB′ is adjacent and parallel to section AA′. As shown in FIG.6C, a portion of the body 613 is shown under the switch 605; however,the switching metal 617 does not overlap the body 613, and parasiticelectrostatic forces are avoided.

FIG. 6D shows a cross-section view of the device 600, along section CC′of FIG. 6A, which is along the length of the discontinuous body 613.Thus, FIG. 6D illustrates an example of part of a conductive channelswitching metal 617 coupled to the gate 615 (e.g., with a dielectricinterposed therebetween) disposed within the spacing ‘S’ of the body 613discontinuity, wherein the width ‘Wc’ of the conductive channelswitching metal 617 is less than the spacing ‘S’ of the body 613discontinuity. Thus, the switching metal 617 does not overlap the body613, and parasitic electrostatic forces are avoided.

FIG. 7 shows a top-view of a device 700 which may include an array ofembedded/integrated electromechanical power switches (e.g., MEMS/NEMSdevice) and a plurality of integrated decoupling capacitors. In variousembodiments, the switches and decoupling capacitors of the device 700may be substantially similar to the switch 605 and the decouplingcapacitors 621, 623 of FIGS. 6A, 6B, 6C, and 6D, discussed above.

FIGS. 8A/8B and 9A/9B illustrate an example of a device 800 (e.g., whichmay be substantially the same as the device 600) in operation, togetherwith an equivalent circuit corresponding to a particular operationalstate. FIGS. 8A/8B and 9A/9B also illustrate the idea that theintegrated MEMS/NEMS devices of the present disclosure may be configuredas either a power-switch or as a decoupling capacitor. For example, whenthe MEMS/NEMS switch is OPEN (i.e., in an OFF-state), it becomes acapacitor (C_(OFF)). Referring now to FIG. 8A, illustrated therein isthe device 800 in an OFF state, where an air gap exists between theswitching metal of the switch 805 of the device 800 and the source anddrain of the device 800 such that no electrical connection is made, andthe device 800 exhibits a near-infinite resistance. FIG. 8A also shows a‘spring connection’, which is used to illustrate the folded-flexuregate, as described above. FIG. 8B shows an equivalent circuit 810 of thedevice 800 in an OFF state. In particular, the equivalent circuit 810illustrates the circuit between the source and drain of the device 800,which includes the drain capacitance C_(D) (e.g., gate-to-drainOFF-state capacitance) in series with the source capacitance C_(S)(e.g., gate-to-source OFF-state capacitance). In some embodiments, theOFF-state capacitance (C_(D) in series with C_(S)) may be represented asan equivalent OFF-state capacitance C_(OFF), where1/C_(OFF)=(1/C_(D)+1/C_(S)).

FIG. 9A shows the device 800 in an ON state, where the switch 805 hasbeen actuated, and where a direct electrical connection exists betweenthe switching metal of the switch 805 and the source and drain of thedevice 800 such the direct electrical connection provides a very lowON-state resistance. FIG. 9B shows an equivalent circuit 910 of thedevice 800 in an ON-state. In the ON-state, the drain and source may beconnected directly to each other (e.g., bypassing C_(D) and C_(S)), suchthat the equivalent circuit 910 may be represented as a short betweenthe source and drain.

FIGS. 10A/10B and 11A/11B illustrate an example of using devices of thepresent disclosure to implement a dual power-gate/decoupling capacitorcircuit, such as a circuit 1000. In some embodiments, such asillustrated in the examples of FIGS. 10A and 11A, the constituentcircuit elements ‘S0’, ‘S1’, and ‘S2’ may all include switches (e.g.,such as the switch 605), while not necessarily including separate,dedicated decoupling capacitors (e.g., such as the decoupling capacitors621, 623). Rather, in some embodiments, the switches ‘S0’, ‘S1’, ‘S2’may be appropriately configured (e.g., as either a power gate switch oras a capacitor) as needed for a given application. To be sure, in someembodiments, each of the switches ‘S0’, ‘S1’, ‘S2’ may alternatelyinclude a device such as the device 600, which also includes decouplingcapacitors. As shown in FIGS. 10A and 11A, an inverter in also coupledbetween the gates of switches ‘S0’/‘S2’ and switch ‘S1’. Thus, as shownin the example of FIG. 10A, when an ENABLE signal is high (e.g., equalto 1V, equal to V_(DD), or other high value) and V_(BODY) is also high,switches ‘S0’ and ‘S2’ may be OFF (near infinite resistance) and switch‘S1’ may be ON (very low resistance). FIG. 10B illustrates an equivalentcircuit 1010 corresponding to the operational state shown in FIG. 10A.As illustrated in FIG. 10B, with ‘S1’ providing a ground connection,‘S0’ and ‘S2’ become decoupling capacitors. Referring to the example ofFIG. 11A, when an ENABLE signal is low (e.g., equal to 0V, equal toV_(SS), or other low value) and V_(BODY) is high, switches ‘S0’ and ‘S2’may be ON (very low resistance) and switch ‘S1’ may be OFF (nearinfinite resistance). FIG. 11B illustrates an equivalent circuit 1110corresponding to the operational state shown in FIG. 11A. As illustratedin FIG. 11B, with ‘S2’ providing a ground connection, ‘S1’ becomes adecoupling capacitor.

FIG. 12 illustrates an example of using devices of the presentdisclosure to implement a redundant integrated MEMS/NEMS power gatingcircuit, such as a circuit 1200. In some embodiments, as shown in theexample of FIG. 12, each of a plurality of CPUs (e.g., CPU 1 and CPU 2)has at least 2 sets of power-gate/decoupling capacitor logic (e.g.,logic block 1202 and 1204) to provide a fail-safe redundancy solution.In some embodiments, the secondary set of logic (e.g., logic block 1204)may be used when the primary set of logic (e.g., lock block 1202) failsin some way (e.g., fails to turn ON at an appropriate time). In someembodiments, when not in use, the secondary set of logic may act as adecoupling capacitor, for example as described above with reference toFIGS. 10A/10B and 11A/11B. In such embodiments, the secondary set oflogic, acting as a decoupling capacitor, may thus decouples theVDD_ALWAYS_ON rail from CPU1's switching noise, and hence provide ACcoupling protection for CPU2. In some embodiments, for example, whenCPU1 is OFF, its primary and secondary switch/decoupling capacitor logicblocks (e.g., logic blocks 1202, 1204) may act as decouplingcapacitor(s) for the VDD_ALWAYS_ON rail, and thus reduce CPU2 dynamicIR-drop. Similar functionality may be implemented, for example, by logicblocks 1206 and 1208, shown in FIG. 12. Moreover, the redundantintegrated MEMS/NEMS power gating circuit described above may beextended to any number of CPUs, GPUs, and/or other circuit blocks,without departing from the scope of the present disclosure.

FIGS. 13A/13B and 14A/14B illustrate examples of using devices of thepresent disclosure to implement a multiple power supply switch circuit,such as a circuit 1300, which includes two power supplies V_(DD1) andV_(DD2). While the present example includes two power supplies, it isunderstood than more than two power supplies may also be used withoutdeparting from the scope of the present disclosure. In some embodiments,such as illustrated in the examples of FIGS. 13A and 14A, theconstituent circuit elements ‘S0’, ‘S1’, ‘S2’, and ‘S3’ may all includeswitches (e.g., such as the switch 605), while not necessarily includingseparate, dedicated decoupling capacitors (e.g., such as the decouplingcapacitors 621, 623). Rather, in some embodiments, the switches ‘S0’,‘S1’, ‘S2’, ‘S3’ may be appropriately configured (e.g., as either apower gate switch or as a capacitor) as needed for a given application.To be sure, in some embodiments, each of the switches ‘S0’, ‘S1’, ‘S2’,‘S3’ may alternately include a device such as the device 600, which alsoincludes decoupling capacitors. As shown in FIGS. 13A and 14A, aninverter in also coupled between the gates of switches ‘S0’ and ‘S1’.Also, for both examples shown in FIGS. 13A and 14A, ‘S2’ may remain ON(very low resistance) and ‘S3’ may remain OFF (near infiniteresistance). Now, as shown in the example of FIG. 13A, when an ENABLEsignal is high (e.g., equal to 1V, equal to V_(DD), or other high value)and V_(BODY) is also high, switch ‘S0’ may be OFF (near infiniteresistance) and switch ‘S1’ may be ON (very low resistance). FIG. 13Billustrates an equivalent circuit 1310 corresponding to the operationalstate shown in FIG. 13A. As illustrated in FIG. 13B, ‘S1’ and ‘S2’provide a low resistance path between V_(DD2) and V_(DD_OUT), while ‘S0’and ‘S3’ act as capacitors. Referring to the example of FIG. 14A, whenan ENABLE signal is low (e.g., equal to 0V, equal to V_(SS), or otherlow value) and V_(BODY) is high, switch ‘S0’ may be ON (very lowresistance) and switch ‘S1’ may be OFF (near infinite resistance). FIG.14B illustrates an equivalent circuit 1410 corresponding to theoperational state shown in FIG. 14A. As illustrated in FIG. 14B, ‘S0’and ‘S2’ provide a low resistance path between V_(DD1) and V_(DD_OUT),while ‘S1’ and ‘S3’ act as capacitors.

FIGS. 15A/15B and 16A/16B illustrate examples of using devices of thepresent disclosure to implement an anti-stiction switching circuit, suchas circuits 1500 and 1600. As discussed above with reference to FIG. 5,stiction (i.e., static friction forces) may cause surfaces along whichthe conductive channel contacts the source/drain electrodes to becomeinadvertently stuck to one another (i.e., they may not disconnect),thereby causing the device to remain ON when it should be OFF. Suchstiction-related problems can occur in conventional MEMS/NEMS deviceswhich solely rely on a spring force of the electromechanical device toshut off the MEMS/NEMS device. FIGS. 15A/15B illustrate a solution toovercome this issue using a planar integrated MEMS/NEMS device (e.g., avertical switch), and FIGS. 16A/16B illustrate a solution using alateral integrated MEMS/NEMS switch. Referring first to the example ofFIGS. 15A/15B, an ENABLE signal is connected to the gate, and the ENABLEsignal is also connected to the body through an inverter. Thus, as shownin FIG. 15A, when the ENABLE/gate voltage V_(GATE) is HIGH, the bodyvoltage V_(BODY) is LOW, and the device is ON (very low resistance). Asshown in FIG. 15B, when the ENABLE/gate voltage V_(GATE) is LOW, thebody voltage V_(BODY) is HIGH, and the gate of the MEMS/NEMS device ispushed up (away) from the source/drain by the reverse bias (e.g.,ENABLE=LOW), and the device is OFF (near infinite resistance). Thus,rather than relying solely on the spring force of the electromechanicaldevice to shut off the MEMS/NEMS device, as in conventional MEMS/NEMSdevices, the example of FIGS. 15A/15B provide an embodiment of aMEMS/NEMS device that shuts OFF when it should by application of anelectrostatic force (e.g., the reverse bias), as discussed above.Similarly, referring to the example of FIGS. 16A/16B, an ENABLE signalis connected to the gate, and the ENABLE signal is also connected to thebody through an inverter. Thus, as shown in FIG. 16A, when theENABLE/gate voltage V_(GATE) is HIGH, the body voltage V_(BODY) is LOW,and the device is ON (very low resistance). As shown in FIG. 16B, whenthe ENABLE/gate voltage V_(GATE) is LOW, the body voltage V_(BODY) isHIGH, and the source beams of the lateral integrated MEMS/NEMS devicesare pushed away from the drain contact by the reverse bias (e.g.,ENABLE=LOW), and the device is OFF (near infinite resistance). Thus,rather than relying solely on the spring force of the electromechanicaldevice to shut off the MEMS/NEMS device, as in conventional MEMS/NEMSdevices, the example of FIGS. 16A/16B provide another embodiment of aMEMS/NEMS device that shuts OFF when it should by application of anelectrostatic force (e.g., the reverse bias), as discussed above.

It will be understood that the examples of FIGS. 15A/15B and FIGS.16A/16B are merely exemplary, and the solutions illustrated therein maybe equally applied to any type of MEMS/NEMS device. Thus, in variousembodiments, any type of MEMS/NEMS device that uses an electromechanicalforce (e.g., an applied voltage bias) to shut off the MEMS/NEMS device,rather than relying solely on the spring force of the electromechanicaldevice, are within the scope of the present disclosure. To be sure,while some embodiments of the present disclosure may shut OFF aMEMS/NEMS device by application of an electrostatic force (e.g., thereverse bias), as discussed above, some examples may also shut OFF aMEMS/NEMS device by application of an electrostatic force (e.g., thereverse bias) in conjunction with utilization of the MEMS/NEMS springforce. For instance, while the examples of FIGS. 15A/15B and FIGS.16A/16B illustrated using an electrostatic force to shut OFF theMEMS/NEMS devices shown therein, the examples of FIGS. 15A/15B and FIGS.16A/16B may also take advantage of the MEMS/NEMS spring forces to assistin shutting OFF the device. For example, in some embodiments, when aMEMS/NEMS spring force is used together with an applied electrostaticforce (e.g., applied voltage), the value of the applied electrostaticforce (e.g., applied voltage) may be reduced. In general, application ofan electrostatic force to assist in shutting OFF any type of MEMS/NEMSdevice would serve to improve device reliability, and would provide forMEMS/NEMS device scaling to very small geometries, where for examplespring forces of such scaled devices may not be sufficient to reliablyshut OFF the device.

As a further example of embodiments of the present disclosure ascompared to conventional solutions, FIGS. 15C/16C illustrate anequivalent circuit of a conventional MEMS/NEMS device that relies solelyon MEMS/NEMS spring forces (e.g., as seen by the ENABLE signal not beingconnected to the body through an inverter). Conversely, FIGS. 15D/16Dillustrate an equivalent circuit of a MEMS/NEMS device corresponding toembodiments of the present disclosure (applicable to any type ofMEMS/NEMS device, including those shown in FIGS. 15A/B and FIGS.16A/16B), which include the ENABLE signal connected to the body throughan inverter and thus employ electrostatic forces, with and/or withoutMEMS/NEMS spring forces, to shut OFF the MEMS/NEMS device.

Referring now to FIGS. 17-33, a discussion of at least some methods offabrication, related devices, and other aspects of the presentdisclosure is provided below. Illustrated in FIGS. 17A, 17B, 17C, and17D is an embodiment of a MEMS/NEMS device having integrated decouplingcapacitors. The embodiments illustrated in FIGS. 17A, 17B, 17C, and 17Dare substantially similar to the examples illustrated in FIGS. 6A, 6B,6C, and 6D. However, as shown in the examples of FIGS. 17A, 17B, 17C,and 17D, the gate of the device 1700 may include a plurality ofopenings/holes 1702 (e.g., that may be formed in some cases bypatterning and etching through the gate electrode). In some embodiments,the openings/holes 1702 may be useful in subsequent processing of thedevice 1700. For example, in some embodiments, the openings/holes 1702may used to allow an etchant (e.g., a hydrofluoric acid HF etchant) topass therethrough and etch an underlying oxide layer, thereby releasingthe movable cantilever structure of the MEMS/NEMS device.

FIG. 18 shows a top-view of a device 1800 which may include an array ofembedded/integrated electromechanical power switches (e.g., MEMS/NEMSdevice) and plurality of integrated decoupling capacitors. In variousembodiments, the switches and decoupling capacitors of the device 1800may be substantially similar to those of the device 1700 of FIGS. 17A,17B, 17C, and 17D, which are also substantially similar to the switch605 and the decoupling capacitors 621, 623 of FIGS. 6A, 6B, 6C, and 6D,discussed above.

Referring now to FIG. 19, illustrated therein is a method 1900 ofsemiconductor fabrication including fabrication of a MEMS/NEMS devicehaving integrated decoupling capacitors (e.g., as illustrated in FIGS.17A, 17B, 17C, and 17D). It is understood that the method 1900 includessteps having features of a complementary metal-oxide-semiconductor(CMOS) technology process flow and thus, are only described brieflyherein. Additional steps may be performed before, after, and/or duringthe method 1900, and some process steps described may be replaced oreliminated in accordance with various embodiments of the method 1900.Further, the semiconductor device discussed below with reference to themethod 1900 may include various other devices and features, such asother types of devices such as additional transistors, bipolar junctiontransistors, resistors, capacitors, inductors, diodes, fuses, staticrandom access memory (SRAM) and/or other logic circuits, etc., but issimplified for a better understanding of the inventive concepts of thepresent disclosure. In some embodiments, the semiconductor devicediscussed below with reference to the method 1900 includes a pluralityof semiconductor devices (e.g., transistors), including PFETs, NFETs,etc., which may be interconnected. Moreover, it is noted that theprocess steps of method 1900, including any descriptions given withreference to any of the figures, are merely exemplary and are notintended to be limiting in any way.

The method 1900 begins at block 1902 where a substrate is provided.Referring for example to FIG. 20B, in an embodiment of block 1902, asubstrate is provided. As described above with reference to FIG. 6B, thesubstrate may be formed from and/or include any of a plurality ofmaterials. Additionally, the substrate may include any of a plurality ofIC devices, for example, formed on a front surface of the semiconductorsubstrate. FIG. 20A shows a top-view of a device at an intermediatestage of fabricating an embedded/integrated electromechanical powerswitch (e.g., MEMS/NEMS device). In particular, FIG. 20A shows sectionsAA′ and BB′, which will be referenced in the discussion of thefabrication method that follows. The method 1900 proceeds to block 1904where a patterned metal layer and nitride capping layer are formed.Referring to the examples of sections AA′ and BB′ of FIG. 20B, in anembodiment of block 1904, patterned metal source, drain, body, and gateregions are formed over the substrate, where a dielectric material(e.g., such as a backend low-K dielectric material) electricallyisolates the patterned metal regions from one another. Also, while notexplicitly shown, a dielectric layer may also be formed over thesubstrate, prior to formation of the patterned metal regions, forexample to electrically isolate and/or protect the IC devices within thesubstrate from the patterned metal of the source, drain, body, and gateregions. However, it will be understood that openings may be formed insuch an isolating dielectric layer (e.g., by a patterning and etchingprocess) in order to connect metal layers above the isolating dielectriclayer to devices, circuits, and/or other metal layers or interconnectsbelow the isolating dielectric layer. In some embodiments, the patternedmetal regions may be formed from copper, but other metals mayequivalently be used without departing from the scope of the presentdisclosure. As also shown in sections AA′ and BB′ of FIG. 20B, in anembodiment of block 1904, a capping layer (e.g., such as a siliconnitride capping layer) is formed over the patterned metal regions andthe dielectric material.

The method 1900 proceeds to block 1906 where a first low temperatureoxide layer is formed. Referring to the examples of sections AA′ and BB′of FIG. 20C, in an embodiment of block 1906, a first low temperatureoxide layer is formed over the capping layer (e.g., such as the siliconnitride capping layer). In some embodiments, the first low temperatureoxide layer includes a PECVD oxide layer, which may be deposited ataround 400° C., and which may have a thickness of about 100 nm.

The method 1900 proceeds to block 1908 where a dimple lithography andetch process is performed. Referring to the examples of sections AA′ andBB′ of FIG. 21B, in conjunction with the example of FIG. 21A, and in anembodiment of block 1908, the first low temperature oxide layer and thecapping layer are patterned and etched (e.g., using a dry etch, wetetch, or combination of wet/dry etch) to form contact dimple patterns aswell as to expose regions which will serve as the decoupling capacitors.

The method 1900 proceeds to block 1910 where a second low temperatureoxide layer is formed. Referring to the examples of sections AA′ and BB′of FIG. 21C, in an embodiment of block 1910, a second low temperatureoxide layer is formed over the device having the dimple patterns (asshown in FIG. 21B). In some embodiments, the second low temperatureoxide layer includes a PECVD oxide layer, which may be deposited ataround 400° C., and which may have a thickness of about 100 nm.

The method 1900 proceeds to block 1912 where a switching metal layer isformed. Referring to the examples of sections AA′ and BB′ of FIG. 22A,in an embodiment of block 1912, a switching metal layer is formed overthe device having the second low temperature oxide layer (as shown inFIG. 21C). In some embodiments, the switching metal layer may includeany of a variety of metals such as W, Au, Mo, Ir, or others as known inthe art. In some embodiments, the switching metal layer may have athickness of about 50 nm.

The method 1900 proceeds to block 1914 where a switching metallithography and etch process are performed. Referring to the examples ofsections AA′ and BB′ of FIG. 22C, in conjunction with the example ofFIG. 22B, and in an embodiment of block 1914, the switching metal layeris patterned and etched (e.g., using a dry etch, wet etch, orcombination of wet/dry etch) to form switch contact regions.

The method 1900 proceeds to block 1916 where a contact lithography andetch process are performed. Referring to the examples of sections AA′and BB′ of FIG. 23B, in conjunction with the example of FIG. 23A, and inan embodiment of block 1916, gate contact regions are patterned andetched (e.g., using a dry etch, wet etch, or combination of wet/dryetch). In some embodiments, the gate contact region pattern and etchingprocess includes patterning and etching the first and second lowtemperature oxide layers in the gate contact regions, as shown insection BB′ of FIG. 23B.

The method 1900 proceeds to block 1918 a gate deposition process isperformed. Referring to the examples of sections AA′ and BB′ of FIG.23C, in an embodiment of block 1918, a gate electrode layer is formedover the device having the patterned and etched contact regions (asshown in FIG. 23B). In some embodiments, the gate electrode layerincludes a PECVD layer, which may be deposited at around 410° C., andwhich may have a thickness of between about 500-1000 nm. Additionally,in some embodiments, the gate electrode layer may include apolycrystalline layer. In some embodiments, the gate electrode layer mayinclude a polycrystalline silicon layer. In some embodiments, the gateelectrode layer may include an in-situ doped polycrystalline layer or anin-situ doped polycrystalline silicon layer. In some embodiments, thegate electrode layer may include a silicon germanium layer. While a fewexamples for materials which may be used for the gate electrode layerhave been given, those of ordinary skill in the art will readilyrecognize other materials that may be equivalently be used withoutdeparting from the scope of the present disclosure.

The method 1900 proceeds to block 1920 where a gate lithography and etchprocess are performed. Referring to the examples of sections AA′ and BB′of FIG. 24B, in conjunction with the example of FIG. 24A, and in anembodiment of block 1920, the gate electrode layer is patterned andetched (e.g., using a dry etch, wet etch, or combination of wet/dryetch) to define the MEMS/NEMS device movable gate (e.g., folded flexuregate) and decoupling capacitor regions. In addition, in someembodiments, the gate lithography and etch processes may also be used topattern and etch a plurality of openings/holes that may be used to allowan etchant (e.g., a hydrofluoric acid HF etchant) to pass therethroughand etch an underlying oxide layer, thereby releasing the movablecantilever structure of the MEMS/NEMS device, as described below.

The method 1900 proceeds to block 1922 where a gate release process isperformed. Referring to the examples of sections AA′ and BB′ of FIG.24C, in conjunction with the example of FIG. 24A, and in an embodimentof block 1922, an oxide etch may be performed (e.g., to etch the firstand second low temperature oxide layers), where for example an etchant(e.g., a hydrofluoric acid HF etchant) passes through the plurality ofopenings/holes to thereby release the movable MEMS/NEMS gate structure.While some examples described herein include the plurality ofopenings/holes to help with the oxide etching and gate release, someembodiments may not include such openings/holes but may neverthelessprovide for the gate release process to be successfully performed.

Referring now to FIGS. 25A, 25B, 25C, 25D, and 25E, illustrated thereinis a method of fabrication of a MEMS/NEMS device (which in some examplesmay also include integrated decoupling capacitors) in accordance with a4-terminal scheme. Referring first to the example to FIG. 25A, asubstrate is provided. As described above, the substrate may be formedfrom and/or include any of a plurality of materials, and the substratemay include any of a plurality of IC devices, for example, formed on afront surface of the semiconductor substrate. In some embodiments, thestructure of the device illustrated in FIG. 25A is similar in at leastsome respects to that illustrated in FIG. 22A, where the switching metallayer has been formed over the device structure. Referring to theexample of FIG. 25A, the illustrated switching metal layer may bepatterned and etched, and a gate oxide layer may then be formed over thedevice structure. In some embodiments, the gate oxide layer includes aPECVD oxide layer, an ALD layer, or other oxide layer. In someembodiments, the gate oxide layer has a thickness of about 50-100 nm. Insome embodiments, for example when the oxide layer includes a PECVDoxide layer, the oxide layer may be deposited at around 400° C.

Referring to the example of FIG. 25B, a gate electrode layer is formedover the device having the gate oxide layer (as shown in FIG. 25A). Insome embodiments, the gate electrode layer includes a PECVD layer, whichmay be deposited at around 410° C., and which may have a thickness ofbetween about 500-1000 nm. Additionally, in some embodiments, the gateelectrode layer may include a polycrystalline layer. In someembodiments, the gate electrode layer may include a polycrystallinesilicon layer. In some embodiments, the gate electrode layer may includean in-situ doped polycrystalline layer or an in-situ dopedpolycrystalline silicon layer. In some embodiments, the gate electrodelayer may include a silicon germanium layer. While a few examples formaterials which may be used for the gate electrode layer have beengiven, those of ordinary skill in the art will readily recognize othermaterials that may be equivalently be used without departing from thescope of the present disclosure.

Referring to the example of FIG. 25C, the gate electrode layer (of FIG.25B) is patterned and etched (e.g., using a dry etch, wet etch, orcombination of wet/dry etch) to define the MEMS/NEMS device movable gate(e.g., folded flexure gate), and in some cases also to define decouplingcapacitor regions. In addition, in some embodiments, the gatelithography and etch processes may also be used to pattern and etch aplurality of openings/holes that may be used to allow an etchant (e.g.,a hydrofluoric acid HF etchant) to pass therethrough and etch anunderlying oxide layer, thereby releasing the movable cantileverstructure of the MEMS/NEMS device, as described below.

Referring to the examples of FIGS. 25D and 25E, the patterned and etchedgate electrode layer (of FIG. 25C) is released, for example, using agate release process. FIG. 25D illustrates the BB′ section, for example,as shown in FIG. 17A, and FIG. 25E illustrates the AA′ section, forexample, as shown in FIG. 17A. In various embodiments, the gate releaseprocess may be performed by etching underlying oxide layers (e.g., suchas the first and second low temperature oxide layers), where for examplean etchant (e.g., a hydrofluoric acid HF etchant) passes through theplurality of openings/holes in the gate electrode to thereby release themovable MEMS/NEMS gate structure. While some examples described hereininclude the plurality of openings/holes to help with the oxide etchingand gate release, some embodiments may not include such openings/holesbut may nevertheless provide for the gate release process to besuccessfully performed.

FIG. 26 illustrates an exemplary embodiment of an integratedMEMS/NEMS-decoupling capacitor cell. The exemplary MEMS/NEMS-decouplingcapacitor cell may be fabricated in accordance with one or more of themethods described herein. In addition, FIG. 26 provides sampledimensions for the exemplary MEMS/NEMS-decoupling capacitor cell. Forexample, in some embodiments, the MEMS/NEMS-decoupling capacitor cellsize may be around 1800 μm² (e.g., around 50 μm×36 μm). Also, in someembodiments, a decoupling capacitor size (of the MEMS/NEMS-decouplingcapacitor cell) may be around 936 μm² (e.g., around 468 μm×2 μm). Itwill be understood that these sample dimensions are merely exemplary,and various embodiments may include different MEMS/NEMS-decouplingcapacitor cell sizes and different decoupling capacitor sizes forexample as defined for a particular technology and/or device, circuit,or process requirement, without departing from the scope of thisdisclosure.

With reference now to FIGS. 27-30, a discussion of embodiments includinga three-dimensional (3-D) coupling capacitor is provided. It will beunderstood and appreciated that the devices, structures, and methodsincluding the 3-D coupling capacitor are similar to the devices,structures, and methods that have been described above. Thus, variousaspects of the embodiments including the 3-D coupling capacitor are onlydescribed briefly, for clarity of understanding.

Referring first to FIG. 27, illustrated therein is a device 2700including a MEMS/NEMS device having integrated decoupling capacitors. Insome embodiments, the device 2700 is very similar to the device 1700 ofFIG. 17A or the device of FIG. 26. However, as shown in FIG. 27 thedevice 2700 may include a plurality of 3-D features 2702, which forexample may include fins, ridges, valleys, mesas, and/or other 3-Dfeatures as known in the art. In various embodiments, a purpose of theplurality of 3-D features 2702 includes increasing a surface area of theintegrated decoupling capacitors and thus increasing a capacitance valueof the integrated decoupling capacitors. As shown in the example of FIG.27, the decoupling capacitor area may be around 936 μm² (e.g., includingthe planar area, as shown in FIG. 26) plus around 780 μm² (e.g.,including the vertical area and assuming around a 1 μm metal thickness,as shown in FIG. 27), for a total capacitor area of around 1716 μm²,which in the example of FIG. 27 is around 95% of the entire cell area.

Referring now to FIG. 28, illustrated therein is a method 2800 ofsemiconductor fabrication including fabrication of a MEMS/NEMS devicehaving integrated decoupling capacitors and a plurality of 3-D features.It is understood that the method 2800 is very similar to the method 1900described above and thus some of the discussion below may be abbreviatedfor clarity of understanding. It is further understood that the method2800 includes steps having features of a complementarymetal-oxide-semiconductor (CMOS) technology process flow and thus, areonly described briefly herein. Additional steps may be performed before,after, and/or during the method 2800, and some process steps describedmay be replaced or eliminated in accordance with various embodiments ofthe method 2800. Further, the semiconductor device discussed below withreference to the method 2800 may include various other devices andfeatures, such as other types of devices such as additional transistors,bipolar junction transistors, resistors, capacitors, inductors, diodes,fuses, static random access memory (SRAM) and/or other logic circuits,etc., but is simplified for a better understanding of the inventiveconcepts of the present disclosure. In some embodiments, thesemiconductor device discussed below with reference to the method 2800includes a plurality of semiconductor devices (e.g., transistors),including PFETs, NFETs, etc., which may be interconnected. Moreover, itis noted that the process steps of method 2800, including anydescriptions given with reference to any of the figures, are merelyexemplary and are not intended to be limiting in any way.

The method 2800 begins at block 2802 where a substrate is provided.Referring for example to FIG. 29B, in an embodiment of block 2802, asubstrate is provided. As described above, the substrate may be formedfrom and/or include any of a plurality of materials. Additionally, thesubstrate may include any of a plurality of IC devices, for example,formed on a front surface of the semiconductor substrate. FIG. 29A showsa top-view of a device at an intermediate stage of fabricating anembedded/integrated electromechanical power switch (e.g., MEMS/NEMSdevice). FIG. 29A also shows section AA′, which will be referenced inthe discussion of the fabrication method that follows. The method 2800proceeds to block 2804 where a patterned 3-D metal features and nitridecapping layer are formed. Referring to the example of section AA′ ofFIG. 29B, in conjunction with the example of FIG. 29A, a plurality of3-D features 2902 are shown. Such 3-D features may include fins, ridges,valleys, mesas, and/or other 3-D features as known in the art. In someembodiments, a patterned metal layer (VIAx) is first formed, and thenthe plurality of 3-D features 2902 are formed, for example using themetal (Mx) layer. In various embodiments, the VIAx metal layer, underthe metal layer Mx, is used to connect the metal layer Mx to thecircuits, devices, etc. below (e.g., in the semiconductor substrate). Insome embodiments, the plurality of 3-D features 2902 may be formeddirectly within the initially deposited patterned metal layer. Asdescribed above, while not explicitly shown, a dielectric layer may alsobe formed over the substrate, prior to formation of the patterned metaland 3-D features, for example to electrically isolate and/or protect theIC devices within the substrate from the patterned metal of the source,drain, body, and gate regions. However, it will be understood thatopenings may be formed in such an isolating dielectric layer (e.g., by apatterning and etching process) in order to connect metal layers abovethe isolating dielectric layer to devices, circuits, and/or other metallayers or interconnects below the isolating dielectric layer. As alsoshown in FIG. 29B, in an embodiment of block 2804, a capping layer(e.g., such as a silicon nitride capping layer) is formed over thepatterned metal an 3-D features, as well as the dielectric material.

FIGS. 30A and 30B are substantially similar to FIGS. 29A and 29B;however, a plurality of 3-D features 3002 of FIGS. 30A and 30B may havea different configuration than the 3-D features 2902 of FIGS. 29A and29B. For example, the 3-D features 3002 of FIGS. 30A and 30B may includemesas formed in the metal layer (Mx), disposed over the pattern metal(VIAx) layer. However, as discussed above, various embodiments mayinclude 3-D features such as fins, ridges, valleys, mesas, and/or other3-D features as known in the art.

The method 2800 proceeds to block 2806 where a first low temperatureoxide layer is formed. Referring to the example of section AA′ of FIG.30C, in an embodiment of block 2806, a first low temperature oxide layeris formed over the capping layer (e.g., such as the silicon nitridecapping layer). In some embodiments, the first low temperature oxidelayer includes a PECVD oxide layer, which may be deposited at around400° C., and which may have a thickness of about 100 nm.

The method 2800 proceeds to block 2808 where a dimple lithography andetch process is performed. Referring to the example of section AA′ ofFIG. 30D, in an embodiment of block 2808, the first low temperatureoxide layer, the capping layer, and the backend low-K dielectric arepatterned and etched (e.g., using a dry etch, wet etch, or combinationof wet/dry etch) to form contact dimple patterns as well as to exposeregions which will serve as the decoupling capacitors.

The method 2800 proceeds to block 2810 where a second low temperatureoxide layer is formed. Referring to the example of section AA′ of FIG.30E, in an embodiment of block 2810, a second low temperature oxidelayer is formed over the device having the dimple patterns (as shown inFIG. 30D). In some embodiments, the second low temperature oxide layerincludes a PECVD oxide layer, which may be deposited at around 400° C.,and which may have a thickness of about 100 nm.

The method 2800 proceeds to block 2812 where a switching metal layer isformed. Referring to the example of section AA′ of FIG. 30F, in anembodiment of block 2812, a switching metal layer is formed over thedevice having the second low temperature oxide layer (as shown in FIG.30E). In some embodiments, the switching metal layer may include any ofa variety of metals such as W, Au, Mo, Ir, or others as known in theart. In some embodiments, the switching metal layer may have a thicknessof about 50 nm.

The method 2800 proceeds to block 2814 where a switching metallithography and etch process are performed. Referring to the example ofsection AA′ of FIG. 30G, in an embodiment of block 2814, the switchingmetal layer is patterned and etched (e.g., using a dry etch, wet etch,or combination of wet/dry etch).

While not explicitly illustrated, the method 2800 may also includecontact lithography and etch processes, as described above withreference to the method 1900.

The method 2800 proceeds to block 2816 where a gate deposition processis performed. Referring to the example of section AA′ of FIG. 3011, inan embodiment of block 2816, a gate electrode layer is formed over thedevice having the patterned and etched switching metal layer (as shownin FIG. 30G). In some embodiments, the gate electrode layer includes aPECVD layer, which may be deposited at around 410° C., and which mayhave a thickness of between about 500-1000 nm. Additionally, in someembodiments, the gate electrode layer may include a polycrystallinelayer. In some embodiments, the gate electrode layer may include apolycrystalline silicon layer. In some embodiments, the gate electrodelayer may include an in-situ doped polycrystalline layer or an in-situdoped polycrystalline silicon layer. In some embodiments, the gateelectrode layer may include a silicon germanium layer. While a fewexamples for materials which may be used for the gate electrode layerhave been given, those of ordinary skill in the art will readilyrecognize other materials that may be equivalently be used withoutdeparting from the scope of the present disclosure.

The method 2800 proceeds to block 2818 where a gate lithography and etchprocess are performed. Referring to the example of section AA′ of FIG.30J, in an embodiment of block 2818, the gate electrode layer ispatterned and etched (e.g., using a dry etch, wet etch, or combinationof wet/dry etch) to define the MEMS/NEMS device movable gate (e.g.,folded flexure gate) and 3-D decoupling capacitor regions. In addition,in some embodiments, the gate lithography and etch processes may also beused to pattern and etch a plurality of openings/holes that may be usedto allow an etchant (e.g., a hydrofluoric acid HF etchant) to passtherethrough and etch an underlying oxide layer, thereby releasing themovable cantilever structure of the MEMS/NEMS device, as describedbelow.

The method 2800 proceeds to block 2820 where a gate release process isperformed. Referring to the example of section AA′ of FIG. 30K, in anembodiment of block 2820, an oxide etch may be performed (e.g., to etchthe first and second low temperature oxide layers underneath the switchmovable gate), where for example an etchant (e.g., a hydrofluoric acidHF etchant) passes through the plurality of openings/holes to therebyrelease the movable MEMS/NEMS gate structure. While some examplesdescribed herein include the plurality of openings/holes to help withthe oxide etching and gate release, some embodiments may not includesuch openings/holes but may nevertheless provide for the gate releaseprocess to be successfully performed.

Referring to FIGS. 31 and 32, illustrated therein are figures showingcapacitance values versus capacitor area, for capacitors having avariety of oxide thickness and a variety of dielectric materials. Invarious embodiments, any of options presented in FIGS. 31 and 32 may beused to implement any of the decoupling capacitors, whether planar or3-D, as described above. It is also noted that since embodiments of thepresent disclosure provide for the decoupling capacitor(s) to bedisposed immediately adjacent to the MEMS/NEMS switch, parasiticresistance and/or inductance is very small, thereby enabling thedecoupling capacitor(s), as disclosed herein, to respond faster to anyvoltage demand than a conventional CMOS bypass/decoupling capacitor.FIG. 33 provides a table showing some basic properties of SiO₂ andSi₃N₄, published in June 2002 by Virginia Semiconductor ofFredericksburg, Va., and which may be useful for implementation of oneor more of the embodiments disclosed herein.

FIGS. 34-50 illustrate some additional embodiments within the scope ofthe present disclosure. Referring first to FIGS. 34A/34B, illustratedtherein is an embodiment of a MEMS/NEMS device 3400 having integrateddecoupling capacitors. The embodiments illustrated in FIGS. 34A/34B aresubstantially similar to the examples illustrated in FIGS. 17A/17B.However, as shown in the examples of FIGS. 34A/34B, the device 3400 mayinclude an input decoupling capacitor (e.g., DeCap on VDDin) having alarger area than an output decoupling capacitor (e.g., DeCap on VDDout).Thus, in some examples for the device 3400, a capacitance of the inputdecoupling capacitor (e.g., DeCap on VDDin) is larger than a capacitanceof the output decoupling capacitor (e.g., DeCap on VDDout). In addition,FIGS. 34A/34B provide sample dimensions. For example, in someembodiments, the MEMS/NEMS-decoupling capacitor cell size may be around500 μm², and the decoupling capacitor size (of the MEMS/NEMS-decouplingcapacitor cell) may be around 300 μm². It will be understood that thesesample dimensions are merely exemplary, and various embodiments mayinclude different MEMS/NEMS-decoupling capacitor cell sizes anddifferent decoupling capacitor sizes for example as defined for aparticular technology and/or device, circuit, or process requirement,without departing from the scope of this disclosure.

FIG. 35 shows a top-view of a device 3500 which may include an array ofembedded/integrated electromechanical power switches (e.g., MEMS/NEMSdevice) and plurality of integrated decoupling capacitors. In variousembodiments, the array of the device 3500 may be similar to the array ofthe device 1800, and the switches and decoupling capacitors of thedevice 3500 may be similar to those of the device 1700, which are alsosubstantially similar to the switch 605 and the decoupling capacitors621, 623 of FIGS. 6A, 6B, 6C, and 6D, discussed above. However, at leastsome of the embedded/integrated electromechanical power switches (e.g.,MEMS/NEMS device) and plurality of integrated decoupling capacitors ofthe device 3500 also includes one or more input decoupling capacitors(e.g., DeCap on VDDin) having a larger area than one or more outputdecoupling capacitors (e.g., DeCap on VDDout), such as shown in FIGS.34A/34B. Thus, in some examples for the device 3500, a capacitance ofone or more input decoupling capacitors (e.g., DeCap on VDDin) of thearray of the device 3500 is larger than a capacitance of one or moreoutput decoupling capacitor (e.g., DeCap on VDDout) connected to thesame device of the array to which the input decoupling capacitor isconnected.

FIGS. 36A/36B illustrates an embodiment of a MEMS/NEMS device 3600having integrated decoupling capacitors. The embodiments illustrated inFIGS. 36A/36B are substantially similar to the examples illustrated inFIGS. 17A/17B and 34A/34B. However, as shown in the examples of FIGS.36A/36B, the device 3600 may include an input decoupling capacitor(e.g., DeCap on VDDin) while not including an output decouplingcapacitor.

Referring now to FIGS. 37-50, and with reference first to FIGS. 37/38,illustrated therein is a top-view and cross-section view, respectively,of an embodiment of a 3D (e.g., vertical) multi-layer capacitor 3700which may for example be implemented in and/or used in conjunction withthe various MEMS/NEMS devices discussed above. FIGS. 39/40 illustratesan array 3900 (e.g., a 2×2 array), which may include an array ofmulti-layer capacitors (e.g., such as the multi-layer capacitor 3700),where the array 3900 may be implemented in and/or used in conjunctionwith the various MEMS/NEMS devices discussed above. It will understoodthat in various embodiments, the array 3900 may include any other numberof devices to form an array of any of a variety of sizes (e.g., 3×3,4×4, etc.), as desired for a particular application.

With reference to FIGS. 41-50, illustrated therein is a process flowwhich may be used to fabricate a multi-layer capacitor, for example,such as the multi-layer capacitors 3700. As shown in FIG. 41,illustrated therein is the device 3700 at an intermediate stage ofprocessing. In particular and by way of example, FIG. 41 shows a CMOSwafer at a post-Mx processing stage. As shown in FIG. 42, a lithographypatterning process and etching process may be performed to fabricate acapacitor trench 4202. In some examples, the capacitor trench 4202 hasdimensions L×W×Depth of about 2×2×3 microns. Then, as shown in FIG. 43,a first dielectric may be deposited over the device 3700 and within thetrench 4202. A first electrode (e.g., ‘Electrode 1’) contact may also bepatterned and the first dielectric etched, so as to expose the Mx metalfor the first electrode contact. In some embodiments, the firstdielectric includes SiO₂, Si₃N₄, a high-K dielectric layer, or otherappropriate layer, and the first dielectric may have a thickness ofaround 5-50 nm. Thereafter, as shown in FIG. 44, a first electrode metallayer may be deposited, followed by a lithography and etch process(e.g., to expose the first dielectric over a second electrode contactregion). In some embodiments, the first electrode metal layer mayinclude TiN, HfN, or other appropriate material, and may have athickness of about 40-50 nm. In FIG. 45, a second dielectric may bedeposited over the device 3700 and within the trench 4202. A secondelectrode (e.g., ‘Electrode 2’) contact may also be patterned and theunderlying first and second dielectric etched, so as to expose the Mxmetal for the second electrode contact. In some embodiments, the seconddielectric includes SiO₂, Si₃N₄, a high-K dielectric layer, or otherappropriate layer, and the second dielectric may have a thickness ofaround 5-50 nm. Thereafter, as shown in FIG. 46, a second electrodemetal layer may be deposited, followed by a lithography and etch process(e.g., to remove the second electrode metal layer over the firstelectrode contact region). In some embodiments, the second electrodemetal layer may include TiN, HfN, or other appropriate material, and mayhave a thickness of about 40-50 nm. FIGS. 47, 48, 49, and 50 illustratean example of repeating the steps of FIGS. 43, 44, 45, and 46, forexample, to build up a capacitance of the device 3700. In variousembodiments, the repetition of the steps of FIGS. 43, 44, 45, and 46, asshown in FIGS. 47, 48, 49, and 50, may be repeated as many times asdesired in order to achieve a target capacitance value for the device3700.

With reference to FIG. 51, illustrated therein is a method ofdissipating heat (transferring heat) using a MEMS/NEMS device 5100having integrated decoupling capacitors, according to some embodiments.It is understood that the method of dissipating heat illustrated withreference to FIG. 51 may be applied to (used in conjunction with)various other embodiments of MEMS/NEMS devices discussed herein, forexample, with reference to other figures of this disclosure. In someexamples, the heat generated by high current flow (e.g., Joule heating)within the device 5100 may be dissipated through the electrode'smaterials of the decoupling capacitors. In some embodiments, heat may begenerated by IC devices within an IC device layer 5200 of the substrateand channeled through one or more contacts, vias, metal interconnectlayers, through electrodes of the decoupling capacitor(s), and throughthe power supply pad and/or grounding pad, such that the heat isdissipated outside of (away from) the device 5100, for example, to thesurrounding ambient, to a coupled heatsink, or other convenient heatdissipation pathway. In some embodiments, larger decoupling capacitorelectrode sizes (e.g., including area and thickness) provide forincreased decoupling capacitance, as well as for quicker heatdissipation, thereby more quickly reducing an IC operating temperature,resulting in lower leakage current, better performance, and improvedreliability.

FIGS. 52, 53, 54, 55, 56, 57, and 58 illustrate some additionalembodiments within the scope of the present disclosure. In particular,FIGS. 52, 53, 54, 55, 56, 57, and 58 illustrate the structure andoperation of various embodiments of a MEMS/NEMS device useful forimplementing a dual electrostatic forces (e.g., dual eForces)I-MEMS/I-NEMS structure. In some aspects, the embodiments discussed withrespect to FIGS. 52, 53, 54, 55, 56, 57, and 58 may provide analternative anti-stiction switching solution. Referring first to FIGS.52 and 53, illustrated therein is a top view and a cross-section view,respectively, of an embodiment of a dual eForces MEMS/NEMS device 5200.In some examples, when an applied voltage at the bottom body (V_Body1)is equal to about Vdd (e.g., around 1V) and an applied voltage at thetop body (V_Body2) is equal to about Vss(e.g., Ground or around 0V),then the dual eForces MEMS/NEMS device 5200 may function as a PMOStransistor. In some cases, when the applied voltage at the bottom body(V_Body1) is equal to about Vss (e.g., Ground or around 0V) and theapplied voltage at the top body (V_Body2) is equal to about Vdd (e.g.,around 1V), then the dual eForces MEMS/NEMS device 5200 may function asan NMOS transistor.

The operation of an embodiment of a dual eForces I-MEMS/I-NEMS structureis discussed in more detail with reference to FIGS. 54, 55, 56, and 57.For example, FIG. 54 illustrates an embodiment of a dual eForcesMEMS/NEMS device 5400 turning on/switching on, or turned on/switched on,and functioning as a PMOS transistor. By way of example, the appliedvoltage between the bottom body (Body1) and the Gate may create anelectrostatic force (Felec) that pushes the movable gate downward,turning on the device. The electrostatic force turning on the device maybe greater than the spring force, as shown. FIG. 55 illustrates anembodiment of the dual eForces MEMS/NEMS device 5400 turningoff/switching off, or turned off/switched off, and functioning as a PMOStransistor. By way of example, the applied voltage between the top body(Body2) and the Gate may create a reverse electrostatic force (Felec)that pulls the movable gate upward, turning off the device. Theelectrostatic force turning off the device, plus the spring force, maybe greater than the stiction force, as shown. In some embodiments, thedual eForces MEMS/NEMS device 5400 provides a substantially (about 100%)stiction free solution.

Referring now to FIG. 56, illustrated therein is an embodiment of thedual eForces MEMS/NEMS device 5400 turning on/switching on, or turnedon/switched on, and functioning as an NMOS transistor. As discussedabove, the polarity of voltages applied to the bottom body and top body(Body 1/Body 2) may be reversed in order to switch operation betweenPMOS and NMOS transistor types. By way of example, and as shown in FIG.56, the applied voltage between the bottom body (Body1) and the Gate maycreate an electrostatic force (Felec) that pushes the movable gatedownward, turning on the device. The electrostatic force turning on thedevice may be greater than the spring force, as shown. FIG. 57illustrates an embodiment of the dual eForces MEMS/NEMS device 5400turning off/switching off, or turned off/switched off, and functioningas an NMOS transistor. By way of example, the applied voltage betweenthe top body (Body2) and the Gate may create a reverse electrostaticforce (Felec) that pulls the movable gate upward, turning off thedevice. The electrostatic force turning off the device, plus the springforce, may be greater than the stiction force, as shown. It will beunderstood that the above structures are merely exemplary, and variousembodiments may include different MEMS/NEMS devices or circuitimplementations, for example having different dimensions and/orconfigurations, as defined for a particular technology and/or device,circuit, or process requirement, without departing from the scope ofthis disclosure. As merely one example, FIG. 58 illustrates a top viewof an embodiment of a dual eForces MEMS/NEMS circuit 5800 including aplurality of dual eForces MEMS/NEMS devices. It will understood that invarious embodiments, the circuit 5800 may include any other number ofdevices to form an array of any of devices of a variety of sizes (e.g.,3×3, 4×4, etc.), as desired for a particular application.

With reference to FIGS. 59-76, illustrated therein is a process flowwhich may be used to fabricate dual eForces MEMS/NEMS devices and/orcircuits, for example, such as the dual eForces MEMS/NEMS device 5200,the dual eForces MEMS/NEMS device 5400, and the dual eForces MEMS/NEMScircuit 5800. As shown in FIG. 59, illustrated therein is the device5900 at an intermediate stage of processing. In particular and by way ofexample, FIG. 59 shows a CMOS wafer at a post-Mx processing stage (e.g.,with metal areas to contact a MEMS structure). As shown in FIG. 60, afirst low temperature oxide is deposited and subsequently patterned andetched at contact dimples and decoupling capacitor (DeCap) areas. Insome embodiments, the first low temperature oxide includes a PECVD oxidelayer, which may be deposited at less than around 400° C., and which mayhave a thickness of about 100 nm. Thereafter, as shown in FIGS. 61 and62, a second low temperature oxide and switching metal are deposited,and the switching metal is patterned and etched to form the switchcontact and DeCap electrode regions. In some embodiments, the second lowtemperature oxide includes a PECVD oxide layer, which may be depositedat less than around 400° C., and which may have a thickness of about 100nm. In some embodiments, the switching metal may include any of avariety of metals such as W, Au, Mo, Ir, or others as known in the art.In some embodiments, the switching metal may have a thickness of about50 nm and may be deposited by PVD. As shown in FIG. 63, a MEMS/NEMS gatedielectric may then be deposited. In some embodiments, the MEMS/NEMSgate dielectric includes a PECVD layer of SiO₂ or SiN, which may bedeposited at less than around 400° C., and which may have a thickness ofabout 100 nm. In some cases, the MEMS/NEMS gate dielectric may bedeposited by ALD and may have a thickness of about 50 nm. Followingthat, a contact lithography and etch process may be performed to definea MEMS/NEMS gate contact region (FIG. 64). Referring to FIG. 65, theMEMS/NEMS gate material is deposited (e.g., such as polysilicon), and aMEMS/NEMS gate lithography and etch process is performed to define themovable gate and DeCap regions. In some embodiments, the MEMS/NEMS gatematerial includes a PECVD or PVD-deposited layer, which may be depositedat less than around 400° C., and which may have a thickness of betweenabout 500-1000 nm. In some embodiments, the MEMS/NEMS gate material mayinclude an in-situ doped polycrystalline layer. In some embodiments, theMEMS/NEMS gate material may include a silicon germanium layer or agermanium layer. As shown in FIG. 66, a movable MEMS/NEMS gate releaseprocess is performed, which may include an oxide etching process torelease the movable structures. Referring to FIGS. 67 and 68, a firstsacrificial layer may be deposited and a CMP process performed, wherethe CMP process may be designed to stop at the MEMS/NEMS gate (e.g.,polysilicon MEMS/NEMS gate). In some embodiments, the first sacrificiallayer includes a PECVD layer of SiO₂, which may be deposited at lessthan around 400° C., and which may have a thickness of about 3-5microns. As shown in FIG. 69, a first sacrificial layer lithography andetching process may be performed to define an area for MEMS/NEMS switchcapping. With reference to FIGS. 70 and 71, a second sacrificial layeris deposited and a second sacrificial layer lithography and etchingprocess may be performed to define an area for the MEMS/NEMS switch. Insome embodiments, the second sacrificial layer includes a PECVD layer ofSiO₂, which may be deposited at around 400° C., and which may have athickness of about 0.2-0.5 microns. As shown in FIGS. 72 and 73, acapping layer is then deposited, and a capping layer lithography andetching process is performed to protect the area of the MEMS/NEMSswitch. In some embodiments, the capping layer includes a sputteredlayer of SiN or AN, which may be deposited at around 400° C., and whichmay have a thickness of about 0.2-0.5 microns. FIG. 74 illustratesdeposition of a top body layer, followed by a top body lithography andetching process to define the top body pattern. In some embodiments, thetop body layer includes a PECVD or PVD-deposited layer, which may bedeposited at less than around 400° C., and which may have a thickness ofbetween about 500-1000 nm. In some embodiments, the top body layer mayinclude an in-situ doped polycrystalline layer. In some embodiments, thetop body layer may include a silicon germanium layer or a titaniumlayer. As shown in FIG. 75, the sacrificial layers (e.g., the first andsecond sacrificial layers) may be etched, for example, using a vapor HFetching process or other appropriate process. Thereafter, as shown inFIG. 76, a back-end dielectric may be deposited. In some embodiments,the back-end dielectric includes a PECVD layer of SiO₂ or SiN, or alow-K dielectric material, which may be deposited at less than around400° C., and which may have a thickness of about 500-1000 nm. In somecases, the back-end dielectric may include an in-situ dopedpolycrystalline layer. While FIGS. 59-76 provide some examples ofmaterials and processes that may be used to perform a given step and/orto form a given layer, it will be understood that such examples aremerely exemplary, and other appropriate materials and/or processes mayequivalently be used without departing from the scope of the presentdisclosure. As one example, various materials, processes, andtechnologies which may be implemented in various embodiments throughoutthe present disclosure are described by Hongwei Qu, “CMOS MEMSFabrication Technologies and Devices”, Micromachines, 2016, 7, 14, thecontents of which are hereby incorporated by reference in theirentirety.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Forexample, Appendix A, which includes an appendix to the presentspecification, includes a slide deck illustrating various additionalembodiments, in accordance with one or more embodiments describedherein. The contents of Appendix A are incorporated by reference hereinin their entirety. In addition, many modifications may be made to adapta particular system, device or component thereof to the teachings of theinvention without departing from the essential scope thereof. Therefore,it is intended that the invention not be limited to the particularembodiments disclosed for carrying out this invention, but that theinvention will include all embodiments falling within the scope of theappended claims. Moreover, the use of the terms first, second, etc. donot denote any order or importance, but rather the terms first, second,etc. are used to distinguish one element from another.

Furthermore, while the above discussion is meant to be illustrative ofthe principles and various embodiments of the present invention,numerous variations and modifications will become apparent to thoseskilled in the art once the above disclosure is fully appreciated. Forexample, unless otherwise indicated, any one or more of the layers setforth herein can be formed in any number of suitable ways (e.g., withspin-on techniques, sputtering techniques (e.g., magnetron and/or ionbeam sputtering), thermal growth techniques, deposition techniques suchas chemical vapor deposition (CVD), physical vapor deposition (PVD)and/or plasma enhanced chemical vapor deposition (PECVD), or atomiclayer deposition (ALD)). Also, unless otherwise indicated, any one ormore of the layers can be patterned in any suitable manner (e.g., vialithographic and/or etching techniques). It is intended that thefollowing claims be interpreted to embrace all such variations andmodifications.

What is claimed is:
 1. A semiconductor device comprising: asemiconductor substrate including at least one integrated circuit deviceon a front surface of the semiconductor substrate; an insulating layeron the front surface including over the at least one integrated circuitdevice; an electromechanical power switch on the insulating layer,wherein the electromechanical power switch includes a source and adrain, a body region disposed between the source and the drain, and agate including a switching metal layer; and a first decoupling capacitorformed over at least one of the source and the drain.
 2. Thesemiconductor device of claim 1, wherein the first decoupling capacitorincludes a 3D capacitor having a plurality of 3D features.
 3. Thesemiconductor device of claim 2, wherein the plurality of 3D featuresinclude at least one of fins, ridges, valleys, or mesas.
 4. Thesemiconductor device of claim 2, wherein the plurality of 3D featuresinclude 3D metal features, and wherein the first decoupling capacitorfurther includes a dielectric layer formed over the 3D metal featuresand an electrode formed over the dielectric layer.
 5. The semiconductordevice of claim 1, wherein the first decoupling capacitor includes a 3Dmulti-layer capacitor, and wherein the 3D multi-layer capacitorcomprises: a trench portion; a first metal region on the insulatinglayer and adjacent to a first side of the trench portion; a second metalregion on the insulating layer and adjacent to a second side of thetrench portion opposite the first side of the trench portion; a pair ofinterdigitated metal electrodes disposed within the trench portion,wherein a first electrode of the pair of interdigitated metal electrodescontacts the first metal region, and wherein a second electrode of thepair of interdigitated metal electrodes contacts the second metalregion; and a plurality of dielectric layers disposed within the trenchportion and between neighboring electrodes of the pair of interdigitatedmetal electrodes.
 6. The semiconductor device of claim 5, wherein thetrench portion extends into the insulating layer.
 7. The semiconductordevice of claim 1, wherein the body region includes a first body portionand a second body portion spaced a distance from the first body portionand defining a body discontinuity therebetween, and wherein theswitching metal layer is disposed over the body discontinuity.
 8. Thesemiconductor device of claim 1, further comprising: a second decouplingcapacitor formed over the other of the at least one of the source andthe drain, wherein the second decoupling capacitor includes a 3Dcapacitor having a plurality of 3D features.
 9. A semiconductor devicecomprising: a semiconductor substrate including at least one integratedcircuit device on a front surface of the semiconductor substrate; aninsulating layer on the front surface including over the at least oneintegrated circuit device; an electromechanical power switch on theinsulating layer, wherein the electromechanical power switch includes asource and a drain, a body region disposed between the source and thedrain, and a gate including a switching metal layer; and a first 3Dcapacitor formed over at least one of the source and the drain.
 10. Thesemiconductor device of claim 9, further comprising: a second 3Dcapacitor formed over the other of the at least one of the source andthe drain.
 11. The semiconductor device of claim 10, wherein at leastone of the first 3D capacitor and the second 3D capacitor includes fins,ridges, valleys, or mesas.
 12. The semiconductor device of claim 10,wherein at least one of the first 3D capacitor and the second 3Dcapacitor includes a 3D multi-layer capacitor, and wherein the 3Dmulti-layer capacitor comprises: a trench portion; a first metal regionon the insulating layer and adjacent to a first side of the trenchportion; a second metal region on the insulating layer and adjacent to asecond side of the trench portion opposite the first side of the trenchportion; a pair of interdigitated metal electrodes disposed within thetrench portion, wherein a first electrode of the pair of interdigitatedmetal electrodes contacts the first metal region, and wherein a secondelectrode of the pair of interdigitated metal electrodes contacts thesecond metal region; and a plurality of dielectric layers disposedwithin the trench portion and between neighboring electrodes of the pairof interdigitated metal electrodes.
 13. A semiconductor devicecomprising: a semiconductor substrate including at least one integratedcircuit device on a front surface of the semiconductor substrate; aninsulating layer on the front surface including over the at least oneintegrated circuit device; an electromechanical power switch on theinsulating layer, wherein the electromechanical power switch includes asource and a drain, a body region disposed between the source and thedrain, and a gate including a switching metal layer; and a 3Dmulti-layer decoupling capacitor, the 3D multi-layer decouplingcapacitor comprising: a trench portion; a first metal region on theinsulating layer and adjacent to a first side of the trench portion; asecond metal region on the insulating layer and adjacent to a secondside of the trench portion opposite the first side of the trenchportion; a pair of interdigitated metal electrodes disposed within thetrench portion, wherein a first electrode of the pair of interdigitatedmetal electrodes contacts the first metal region, and wherein a secondelectrode of the pair of interdigitated metal electrodes contacts thesecond metal region; and a plurality of dielectric layers disposedwithin the trench portion and between neighboring electrodes of the pairof interdigitated metal electrodes.
 14. The semiconductor device ofclaim 13, wherein the trench portion extends into the insulating layer.15. The semiconductor device of claim 13, wherein the first electrode ofthe pair of interdigitated metal electrodes includes at least two firstmetal lines.
 16. The semiconductor device of claim 15, wherein the atleast two first metal lines are interposed by a portion of the secondelectrode.
 17. The semiconductor device of claim 13, wherein the secondelectrode of the pair of interdigitated metal electrodes includes atleast two second metal lines.
 18. The semiconductor device of claim 17,wherein the at least two second metal lines are interposed by a portionof the first electrode.
 19. The semiconductor device of claim 13,wherein the first electrode of the pair of interdigitated metalelectrodes includes a first plurality of metal lines, wherein the firstplurality of metal lines contact each other over the first metal region,and wherein one of the first plurality of metal lines directly contactsthe first metal region.
 20. The semiconductor device of claim 13,wherein the second electrode of the pair of interdigitated metalelectrodes includes a second plurality of metal lines, wherein thesecond plurality of metal lines contact each other over the second metalregion, and wherein one of the second plurality of metal lines directlycontacts the second metal region.